Homemade Vegetarian Irish Stew

Here is my favorite vegetarian Irish stew recipe, with hearty lentils, chunky vegetables, cremini mushrooms for a meaty bite, and Guinness for that deep, rich flavor.

This stew has become our go-to comfort meal on cold Portland evenings. I love that it’s just as filling and satisfying as traditional Irish stew, but completely plant-based. Plus, it tastes even better the next day!

What Kind of Lentils Should I Use?

Green lentils are the best choice for this vegetarian Irish stew because they hold their shape well during the long cooking process and won’t turn mushy on you. You can find them at pretty much any grocery store, usually in the dried beans section or the bulk bins. If you can’t find green lentils specifically, brown lentils will work in a pinch and have a similar texture. Just avoid red or yellow lentils for this recipe since they break down quickly and will turn your stew into more of a thick soup. Make sure to rinse your lentils in a strainer before adding them to remove any dust or debris.

Options for Substitutions

This stew is pretty forgiving when it comes to swaps, so here are some options if you need to make changes:

• Guinness: If you don’t have Guinness or prefer not to use beer, replace it with an equal amount of vegetable broth plus 1 tablespoon of soy sauce and 1 teaspoon of molasses to mimic that deep, rich flavor.
• Green lentils: Brown lentils work just as well and hold their shape nicely. Avoid red lentils though – they’ll turn mushy and break down too much in this recipe.
• Cremini mushrooms: Regular white button mushrooms are a fine substitute. For more flavor, try a mix of mushrooms like shiitake or portobello, just chop them to similar sizes.
• Turnips: Not a fan of turnips? Swap them with parsnips, sweet potatoes, or extra potatoes. Keep the cooking time the same since they all soften at similar rates.
• Russet potatoes: Yukon gold or red potatoes work well too. They’ll hold their shape a bit better than russets, which tend to break down more.
• Flour: For a gluten-free version, use cornstarch (about 3 tablespoons) or a gluten-free flour blend in the same amount.

Watch Out for These Mistakes While Cooking

The biggest mistake you can make with this stew is skipping the mushroom browning step – those 10-12 minutes of cooking are what develop the deep, meaty flavor that makes this vegetarian dish so satisfying, so resist the urge to rush it. Another common error is adding the Guinness without scraping up all those browned bits from the bottom of the pan, which are packed with flavor and help thicken your stew. Make sure to cut your potatoes, turnips, and carrots into similar-sized chunks (about 1-inch pieces) so everything cooks evenly – nobody wants mushy carrots and hard potatoes in the same bowl. Finally, if your stew looks too thin at the end of cooking, remove the lid and let it cook on high for an extra 20-30 minutes to thicken up, or mash a few potato pieces against the side of the slow cooker to naturally thicken the broth.

What to Serve With Vegetarian Irish Stew?

This hearty stew is pretty filling on its own, but I love serving it with thick slices of crusty bread or Irish soda bread for soaking up all that rich Guinness gravy. A simple side of buttered cabbage or roasted Brussels sprouts adds a nice fresh element without making the meal feel too heavy. If you want to go all out, whip up some garlic butter and brush it on warm dinner rolls – they’re perfect for mopping up your bowl. Since the stew already has plenty of vegetables and lentils, you really just need something on the side for dipping and you’re good to go.

Storage Instructions

Store: This stew actually gets better after a day or two in the fridge! Store it in an airtight container for up to 5 days. The flavors really meld together nicely, and the lentils soak up even more of that rich Guinness broth.

Freeze: Irish stew freezes really well for up to 3 months. Let it cool completely, then portion it out into freezer-safe containers. Just keep in mind that the potatoes might get a bit softer after freezing, but the flavor will still be great.

Reheat: Warm it up on the stovetop over medium-low heat, stirring occasionally until heated through. You might need to add a splash of vegetable broth or water since the lentils tend to absorb liquid as they sit. In the microwave, heat on medium power in 2-minute intervals, stirring between each one.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1550-1750
• Protein: 65-75 g
• Fat: 20-26 g
• Carbohydrates: 310-340 g

Ingredients

For the sautéed base:

• 1.5 tbsp olive oil (I prefer Bertolli for a mild sauté)
• 3 celery stalks
• 1 large onion
• 12 oz cremini mushrooms (sliced into 1/4-inch pieces for a meaty texture)
• 1/3 cup flour (I always use King Arthur all-purpose flour)
• 14.9 oz guinness

For the stew:

• 2 russet potatoes (peeled and cut into large 1.5-inch chunks)
• 2 turnips
• 3 large carrots
• 1.5 cups green lentils
• 3 tbsp tomato paste (I like Hunt’s for its deep color and richness)
• 2.5 tsp dijon mustard
• 3 bay leaves
• 2.5 tsp paprika
• 1 tbsp sugar
• 1.25 tbsp salt
• 1.5 tsp black pepper
• 6 cups vegetable broth

For the garnish:

• fresh parsley

Step 1: Prepare All Vegetables and Aromatics

• 3 celery stalks
• 1 large onion
• 2 russet potatoes
• 2 turnips
• 3 large carrots
• 12 oz cremini mushrooms
• 1.5 cups green lentils

Dice the onion into medium pieces and chop the celery stalks into 1/2-inch pieces.

Peel and cut the russet potatoes into large 1.5-inch chunks, then peel and cut the turnips into similar-sized pieces.

Peel and cut the carrots into 1-inch rounds or chunks.

Slice the cremini mushrooms into 1/4-inch pieces—this thickness is key for creating that meaty texture that makes vegetarian stew satisfying.

Measure out the lentils, rinse them if desired, and set aside.

This prep work ensures everything cooks evenly and you’re ready to build flavor efficiently.

Step 2: Sauté Aromatics and Build the Base

• 1.5 tbsp olive oil
• 1 large onion
• 3 celery stalks

Heat 1.5 tbsp olive oil in a large pot or Dutch oven over medium-high heat.

Add the diced onion and celery, cooking for 5-7 minutes until softened and the onion becomes translucent.

This step develops a sweet, savory foundation—don’t skip the browning time as it builds essential flavor depth for the stew.

Transfer the softened vegetables to your slow cooker.

Step 3: Brown Mushrooms and Develop Deep Flavor

• 12 oz cremini mushrooms
• 1/3 cup flour

In the same pot (don’t wash it—those browned bits add flavor), add the sliced mushrooms over medium-high heat.

Cook for 10-12 minutes, stirring occasionally, until they release their moisture and begin to brown and caramelize.

This is where the mushrooms develop that meaty, umami-rich character that gives vegetarian stew its satisfying depth.

Once they’re browned and any excess liquid has evaporated, sprinkle the flour over them and stir constantly for 1-2 minutes to cook out the raw flour taste and create a light roux.

Step 4: Deglaze with Guinness and Transfer to Slow Cooker

• 14.9 oz guinness
• cooked onions and celery from Step 2
• browned mushroom mixture from Step 3

Pour the Guinness into the pot with the mushroom mixture, using a wooden spoon to scrape up all the flavorful browned bits stuck to the bottom—this technique is called deglazing and it captures concentrated flavor.

Let it bubble gently for about 1 minute, then transfer the entire mixture (mushrooms, liquid, and all) to the slow cooker with the cooked onions and celery.

I like using Guinness because its slight bitterness and roasted notes add complexity that elevates the entire stew.

Step 5: Build the Stew and Set for Long Cooking

• 2 russet potatoes
• 2 turnips
• 3 large carrots
• 1.5 cups green lentils
• 3 tbsp tomato paste
• 2.5 tsp dijon mustard
• 2.5 tsp paprika
• 1 tbsp sugar
• 1.25 tbsp salt
• 1.5 tsp black pepper
• 3 bay leaves
• 6 cups vegetable broth

Add the prepared potatoes, turnips, carrots, and green lentils to the slow cooker.

In a small bowl, whisk together the tomato paste, Dijon mustard, paprika, sugar, salt, and black pepper until smooth, then add this mixture to the slow cooker.

Pour in the vegetable broth and add the bay leaves.

Stir everything together thoroughly to combine all ingredients and distribute the spices evenly.

This assembly ensures every spoonful will have balanced flavor and proper seasoning from the start.

Step 6: Cook Low and Slow Until Tender

Cover the slow cooker and cook on low for 8-9 hours or on high for 5-6 hours.

The long cooking time allows the vegetables to become tender, the lentils to fully cook and thicken the broth naturally, and all the flavors to meld together beautifully.

The stew is done when the potatoes and root vegetables are easily pierced with a fork and the lentils are soft.

Step 7: Finish and Serve

• fresh parsley

Remove and discard the bay leaves from the stew.

Taste the stew and adjust seasonings if needed—it should be rich, savory, and deeply flavored.

Ladle into bowls and garnish generously with fresh chopped parsley, which adds brightness and a fresh herbal note that cuts through the richness of the stew.

Homemade Vegetarian Irish Stew

Delicious Homemade Vegetarian Irish Stew recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 2 hours hrs 25 minutes mins

Cook Time 5 hours hrs

Total Time 7 hours hrs 25 minutes mins

Servings 8 servings

Calories 1650 kcal

Ingredients

  

For the sautéed base::

• 1.5 tbsp olive oil (I prefer Bertolli for a mild sauté)
• 3 celery stalks
• 1 large onion
• 12 oz cremini mushrooms (sliced into 1/4-inch pieces for a meaty texture)
• 1/3 cup flour (I always use King Arthur all-purpose flour)
• 14.9 oz guinness

For the stew::

• 2 russet potatoes (peeled and cut into large 1.5-inch chunks)
• 2 turnips
• 3 large carrots
• 1.5 cups green lentils
• 3 tbsp tomato paste (I like Hunt's for its deep color and richness)
• 2.5 tsp dijon mustard
• 3 bay leaves
• 2.5 tsp paprika
• 1 tbsp sugar
• 1.25 tbsp salt
• 1.5 tsp black pepper
• 6 cups vegetable broth

For the garnish::

• fresh parsley

Instructions

 

• Dice the onion into medium pieces and chop the celery stalks into 1/2-inch pieces. Peel and cut the russet potatoes into large 1.5-inch chunks, then peel and cut the turnips into similar-sized pieces. Peel and cut the carrots into 1-inch rounds or chunks. Slice the cremini mushrooms into 1/4-inch pieces—this thickness is key for creating that meaty texture that makes vegetarian stew satisfying. Measure out the lentils, rinse them if desired, and set aside. This prep work ensures everything cooks evenly and you're ready to build flavor efficiently.
• Heat 1.5 tbsp olive oil in a large pot or Dutch oven over medium-high heat. Add the diced onion and celery, cooking for 5-7 minutes until softened and the onion becomes translucent. This step develops a sweet, savory foundation—don't skip the browning time as it builds essential flavor depth for the stew. Transfer the softened vegetables to your slow cooker.
• In the same pot (don't wash it—those browned bits add flavor), add the sliced mushrooms over medium-high heat. Cook for 10-12 minutes, stirring occasionally, until they release their moisture and begin to brown and caramelize. This is where the mushrooms develop that meaty, umami-rich character that gives vegetarian stew its satisfying depth. Once they're browned and any excess liquid has evaporated, sprinkle the flour over them and stir constantly for 1-2 minutes to cook out the raw flour taste and create a light roux.
• Pour the Guinness into the pot with the mushroom mixture, using a wooden spoon to scrape up all the flavorful browned bits stuck to the bottom—this technique is called deglazing and it captures concentrated flavor. Let it bubble gently for about 1 minute, then transfer the entire mixture (mushrooms, liquid, and all) to the slow cooker with the cooked onions and celery. I like using Guinness because its slight bitterness and roasted notes add complexity that elevates the entire stew.
• Add the prepared potatoes, turnips, carrots, and green lentils to the slow cooker. In a small bowl, whisk together the tomato paste, Dijon mustard, paprika, sugar, salt, and black pepper until smooth, then add this mixture to the slow cooker. Pour in the vegetable broth and add the bay leaves. Stir everything together thoroughly to combine all ingredients and distribute the spices evenly. This assembly ensures every spoonful will have balanced flavor and proper seasoning from the start.
• Cover the slow cooker and cook on low for 8-9 hours or on high for 5-6 hours. The long cooking time allows the vegetables to become tender, the lentils to fully cook and thicken the broth naturally, and all the flavors to meld together beautifully. The stew is done when the potatoes and root vegetables are easily pierced with a fork and the lentils are soft.
• Remove and discard the bay leaves from the stew. Taste the stew and adjust seasonings if needed—it should be rich, savory, and deeply flavored. Ladle into bowls and garnish generously with fresh chopped parsley, which adds brightness and a fresh herbal note that cuts through the richness of the stew.