If you ask me, the BLT is already a perfect sandwich.

But when you add sweet, caramelized onions to the mix, you get something that takes this classic to the next level. Crispy bacon, fresh lettuce, and juicy tomatoes pair with golden onions that bring a mild sweetness to every bite.

The onions cook down slowly in their own juices until they’re soft and slightly sweet. They add a new layer of flavor that works perfectly with the smoky bacon and fresh vegetables.

It’s a simple twist on a beloved sandwich that makes lunch feel a little more special.

blt sandwich with onion — Image: theamazingfood.com / All Rights reserved

Why You’ll Love This BLT Sandwich

Quick and easy meal – Ready in just 15-25 minutes, this sandwich is perfect for lunch or a casual dinner when you want something satisfying without much fuss.
Classic comfort food – There’s something so satisfying about the combination of crispy bacon, fresh lettuce, and juicy tomatoes that never gets old.
Simple ingredients – You probably have most of these ingredients in your kitchen already, making it an easy go-to meal.
Extra flavor boost – The addition of turkey, cheese, and red onion takes this beyond a basic BLT, giving you more protein and a nice sharp bite from the onion.
Customizable to your taste – You can easily adjust the mayo, add more or less onion, or swap out the cheese to make it exactly how you like it.

What Kind of Bacon Should I Use?

For the best BLT, you’ll want to use thick-cut bacon rather than thin slices since it holds up better and gives you that satisfying crunch. Regular pork bacon is the classic choice, but turkey bacon works too if you prefer a lighter option. When cooking your bacon, aim for that perfect balance between crispy and chewy – not so crispy that it shatters when you bite into your sandwich, but cooked enough that it’s not floppy. If you’re cooking a lot of bacon at once, try baking it in the oven on a sheet pan at 400°F for more even results than pan-frying.

Options for Substitutions

This BLT sandwich is pretty straightforward, but here are some easy swaps you can make:

Sourdough bread: Any sturdy bread works great here – try whole wheat, rye, or even a good white sandwich bread. Just make sure it’s thick enough to hold all the fillings without getting soggy.
Bacon: Turkey bacon is a lighter option, or you could use ham or even crispy prosciutto for something different. Cook time will vary depending on what you choose.
Deli turkey: Feel free to use ham, roast beef, or even leftover roasted chicken. You could also skip the meat entirely for a classic BLT.
Cheese: Cheddar, Swiss, or provolone all work well. If you want something creamier, try avocado slices instead of cheese.
Red onion: White or yellow onion work just fine, or you could use green onions for a milder flavor. If raw onion isn’t your thing, try caramelized onions instead.
Mayo: Mustard, avocado spread, or even ranch dressing can replace mayo. You could also use a mix of mayo and mustard for extra flavor.
Butter: Olive oil or cooking spray work for toasting the bread, or you can skip this step entirely if you prefer untoasted bread.

Watch Out for These Mistakes While Cooking

The biggest mistake when making BLT sandwiches is using watery tomatoes, which will make your bread soggy and ruin the whole sandwich – always choose firm, ripe tomatoes and pat them dry with paper towels after slicing.

Another common error is not toasting the bread properly, so make sure to butter both sides and toast until golden brown for the perfect crunch that holds up against all the fillings.

Don’t forget to cook your bacon until it’s crispy but not burnt, and drain it on paper towels to remove excess grease that could make your sandwich messy.

For the best results, slice your red onion paper-thin using a sharp knife or mandoline, and assemble your sandwich just before serving to keep everything fresh and prevent the bread from getting soggy.

What to Serve With BLT Sandwich?

A classic BLT sandwich pairs perfectly with crispy potato chips or homemade fries – there’s something about that salty crunch that just works with the smoky bacon and fresh tomatoes. I love serving mine with a simple side of coleslaw or a light cucumber salad to balance out all those rich flavors from the bacon and mayo. If you want something warm, a cup of tomato soup makes for great dipping, especially since you’ve already got those beautiful tomato slices in the sandwich. For a lighter option, try some fresh fruit like watermelon or grapes, which taste amazing alongside the savory bacon and turkey.

Storage Instructions

Best Fresh: BLT sandwiches are really best enjoyed right after making them since the bread can get soggy from the tomatoes and mayo. If you need to save one for later, wrap it tightly in plastic wrap and keep it in the fridge for just a few hours max.

Prep Ahead: Here’s what I do when I want to make these ahead – I keep all the components separate! Cook the bacon and store it in the fridge for up to 5 days, slice your tomatoes and onions the morning you plan to eat, and keep everything in separate containers. Then just assemble when you’re ready to eat.

Pack Smart: If you’re packing this for lunch, try the ‘inside-out’ method – put the mayo and wet ingredients like tomatoes between the meat and cheese instead of directly on the bread. This helps create a barrier so your bread stays nice and crispy until you’re ready to dig in.

Preparation Time	10-15 minutes
Cooking Time	5-10 minutes
Total Time	15-25 minutes
Level of Difficulty	Easy

Estimated Nutrition

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

Calories: 1800-2000
Protein: 80-90 g
Fat: 110-125 g
Carbohydrates: 120-135 g

Ingredients

12 strips cooked bacon
8 slices sourdough loaf
8 rounds tomato
8 slices turkey breast deli meat
4 slices cheese of choice
4 leaves lettuce
Thin rings red onion
Mayonnaise, as desired
4 tbsp butter, for bread

Step 1: Prepare the Griddle and Ingredients

Preheat a large griddle to 375°F.

Meanwhile, gather all your ingredients—sourdough bread, bacon, turkey, cheese, tomato, lettuce, red onion, mayonnaise, and butter—so they’re ready to assemble quickly.

Step 2: Assemble the Sandwiches

8 slices sourdough loaf
mayonnaise, as desired
4 tbsp butter, for bread

Take two slices of sourdough bread and open them like a book.

Spread mayonnaise as desired on the inside faces of each slice, then close the bread back up.

Next, butter the outside faces of the slices—these will touch the griddle and get golden and crisp.

Step 3: Layer the Fillings

12 strips cooked bacon
8 slices turkey breast deli meat
4 slices cheese of choice
8 rounds tomato
4 leaves lettuce
thin rings red onion

Place the buttered bread, butter side down, onto the preheated griddle.

On one slice, layer 1 slice of cheese, 3 strips of cooked bacon, 2 slices of turkey breast deli meat, 2 rounds of tomato, a few thin rings of red onion, and 1 leaf of lettuce for each sandwich.

This hearty stack will create a delicious medley of flavor and texture—I always use freshly sliced tomatoes for maximum juiciness.

Step 4: Grill the Sandwiches

Let the sandwich cook on the griddle until both the bottom and top sides are golden and crispy, and the cheese is beginning to melt.

Carefully monitor the heat to ensure the bread becomes perfectly toasted without burning.

If you like your bread extra crispy, I suggest pressing the sandwich gently with a spatula while it cooks.

Step 5: Assemble and Serve

Once the sandwiches are nicely griddled, place the second slice of bread on top, cut each sandwich in half, and serve immediately.

Enjoy your flavorful, melty creation!