Delicious Mediterranean Tuna Salad Sandwich

I didn’t grow up eating tuna salad with olives and red peppers mixed in. My mom’s version was simple—just tuna, mayo, and maybe some celery if she was feeling fancy. But a few years ago, I tried a Mediterranean-style tuna salad at a café in Portland, and it completely changed how I make this lunch staple.

The difference comes down to swapping out those basic add-ins for ingredients you’d find in a Greek salad—kalamata olives, fresh basil, lemon juice, and red peppers. And here’s the real game-changer: using tuna packed in olive oil instead of water. It sounds like a small thing, but it makes the salad taste way better and gives it a richer texture. Now this is the only way I make tuna salad sandwiches.

What Kind of Tuna Should I Use?

For this Mediterranean tuna salad, you can use either canned tuna in water or oil, depending on your preference. Solid or chunk white albacore tends to have a milder flavor and firmer texture, while chunk light tuna is more budget-friendly and works just as well. If you want to go the extra mile, you can use jarred tuna packed in olive oil for a richer, more authentic Mediterranean taste. Just make sure to drain your tuna well before mixing it with the other ingredients, and if you’re using oil-packed tuna, you might want to cut back slightly on the mayonnaise.

Options for Substitutions

This Mediterranean tuna salad is easy to customize based on what you have in your kitchen:

• Tuna: Canned tuna in water or oil both work great here. You can also swap it out for canned salmon or even cooked chicken breast if you want to switch things up.
• Mayonnaise: Greek yogurt makes a lighter substitute and adds a nice tangy flavor. You can also use half mayo and half Greek yogurt for a middle ground. Avocado mashed up works too if you’re looking for a creamy alternative.
• Kalamata olives: If you don’t have kalamata olives, green olives or black olives from a can will do the trick. You’ll lose some of that briny Mediterranean flavor, but it’ll still taste good.
• Red pepper: Fresh red bell pepper is ideal, but you can use jarred roasted red peppers (just drain and chop them), or swap in yellow or orange bell peppers instead.
• Fresh basil: Dried basil works in a pinch – use about 2 teaspoons instead of the fresh amount. Fresh parsley or dill also make nice substitutes if that’s what you have.
• Bread: Any bread you like works here – whole wheat, sourdough, ciabatta, or even pita pockets. You can also serve this over greens as a salad instead of making sandwiches.

Watch Out for These Mistakes While Cooking

The biggest mistake people make with tuna salad is not draining the tuna well enough, which leads to a watery, runny mixture that makes your bread soggy – press the tuna firmly in a strainer or squeeze it with paper towels to remove excess liquid.

Another common error is adding the mayonnaise while the other ingredients are still wet from rinsing, so make sure to pat dry your red peppers, olives, and basil before mixing everything together.

To keep your sandwich from getting mushy, toast your bread lightly or create a barrier by spreading a thin layer of mayo on the bread before adding the lettuce, which prevents the tuna mixture from soaking through.

Finally, don’t skip finely chopping your red onion and olives – large chunks can overpower the other flavors and make the sandwich harder to eat without everything sliding out.

What to Serve With Mediterranean Tuna Salad Sandwich?

These sandwiches are pretty filling on their own, but I love pairing them with some crispy kettle-cooked potato chips or pita chips for that satisfying crunch. A simple cucumber and tomato salad dressed with olive oil and lemon juice keeps things light and fresh, plus it echoes those Mediterranean flavors already in the sandwich. If you’re looking for something warm, a cup of lemon chicken orzo soup or a basic minestrone works great alongside. You could also serve these with some marinated artichoke hearts, roasted red peppers, or a handful of mixed olives on the side for a full Mediterranean spread.

Storage Instructions

Store: Keep the tuna salad mixture in an airtight container in the fridge for up to 3 days. I like to store it separately from the bread and lettuce so everything stays fresh and crispy. Just assemble your sandwich when you’re ready to eat!

Make Ahead: This tuna salad actually tastes better after sitting for a few hours because the flavors have time to blend together. Mix it up in the morning and let it chill in the fridge until lunchtime. Just wait to add it to the bread until you’re ready to eat so your sandwich doesn’t get soggy.

Pack for Lunch: If you’re taking this to work or school, pack the tuna salad in a small container with an ice pack and bring your bread and lettuce separately. Assemble it right before eating for the best texture and taste.

Estimated Nutrition

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

• Calories: 1100-1300
• Protein: 55-65 g
• Fat: 45-55 g
• Carbohydrates: 120-130 g

Ingredients

• 10 oz tuna (packed in olive oil)
• 1/3 cup red onion (finely diced)
• 1/3 cup mayonnaise
• 1/4 cup kalamata olives (pitted and halved)
• 1/4 cup red pepper (diced)
• 3 tbsp lemon juice (freshly squeezed)
• 1/4 cup basil (chopped)
• 8 slices bread
• romaine lettuce
• 1/4 tsp black pepper

Step 1: Prepare the Ingredients

• 1/3 cup red onion
• 1/4 cup red pepper
• 1/4 cup kalamata olives
• 1/4 cup basil
• 3 tbsp lemon juice

Dice the red onion into fine pieces and set aside.

Dice the red pepper into small, uniform pieces and set aside.

Pit the kalamata olives if not already done, then halve them.

Chop the fresh basil into thin ribbons.

Squeeze the lemon juice fresh and measure out 3 tablespoons—I find fresh lemon juice makes a noticeable difference in brightness compared to bottled, so it’s worth the extra minute.

Step 2: Build the Tuna Salad Base

• 10 oz tuna
• 1/3 cup mayonnaise

Drain the tuna packed in olive oil into a bowl, reserving about 1 tablespoon of the oil.

Add the drained tuna to the bowl and break it apart gently with a fork to create a flaky texture without turning it into a paste.

Add the mayonnaise to the tuna and stir to combine evenly.

I prefer to mix the mayo with the tuna first before adding the other ingredients so it coats everything uniformly and creates a creamy base.

Step 3: Combine and Season the Tuna Salad

• tuna salad base from Step 2
• 1/3 cup red onion
• 1/4 cup red pepper
• 1/4 cup kalamata olives
• 1/4 cup basil
• 3 tbsp lemon juice
• 1/4 tsp black pepper

Add the diced red onion, diced red pepper, halved kalamata olives, and chopped basil to the tuna mixture from Step 2.

Pour in the fresh lemon juice and sprinkle with black pepper.

Gently fold everything together with a fork until all ingredients are evenly distributed and the flavors are well combined.

Taste and adjust seasoning if needed—the lemon juice and olives provide most of the flavor, so go easy on any additional salt.

Step 4: Assemble the Sandwiches

• tuna salad from Step 3
• 8 slices bread
• romaine lettuce

Lay out 4 slices of bread on a clean surface.

Layer romaine lettuce on each slice, making sure the leaves cover the bread evenly—this prevents the bread from getting soggy and adds a crisp texture.

Divide the tuna salad from Step 3 evenly among the four bread slices, spreading it generously over the lettuce layer.

Top each with another slice of bread and press gently to hold everything together.

Slice each sandwich diagonally if desired and serve immediately.

Delicious Mediterranean Tuna Salad Sandwich

Delicious Delicious Mediterranean Tuna Salad Sandwich recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 5 minutes mins

Cook Time 5 minutes mins

Total Time 12 minutes mins

Servings 4 sandwiches

Calories 1200 kcal

Ingredients

  

• 10 oz tuna (packed in olive oil)
• 1/3 cup red onion (finely diced)
• 1/3 cup mayonnaise
• 1/4 cup kalamata olives (pitted and halved)
• 1/4 cup red pepper (diced)
• 3 tbsp lemon juice (freshly squeezed)
• 1/4 cup basil (chopped)
• 8 slices bread
• romaine lettuce
• 1/4 tsp black pepper

Instructions

 

• Dice the red onion into fine pieces and set aside. Dice the red pepper into small, uniform pieces and set aside. Pit the kalamata olives if not already done, then halve them. Chop the fresh basil into thin ribbons. Squeeze the lemon juice fresh and measure out 3 tablespoons—I find fresh lemon juice makes a noticeable difference in brightness compared to bottled, so it's worth the extra minute.
• Drain the tuna packed in olive oil into a bowl, reserving about 1 tablespoon of the oil. Add the drained tuna to the bowl and break it apart gently with a fork to create a flaky texture without turning it into a paste. Add the mayonnaise to the tuna and stir to combine evenly. I prefer to mix the mayo with the tuna first before adding the other ingredients so it coats everything uniformly and creates a creamy base.
• Add the diced red onion, diced red pepper, halved kalamata olives, and chopped basil to the tuna mixture from Step 2. Pour in the fresh lemon juice and sprinkle with black pepper. Gently fold everything together with a fork until all ingredients are evenly distributed and the flavors are well combined. Taste and adjust seasoning if needed—the lemon juice and olives provide most of the flavor, so go easy on any additional salt.
• Lay out 4 slices of bread on a clean surface. Layer romaine lettuce on each slice, making sure the leaves cover the bread evenly—this prevents the bread from getting soggy and adds a crisp texture. Divide the tuna salad from Step 3 evenly among the four bread slices, spreading it generously over the lettuce layer. Top each with another slice of bread and press gently to hold everything together. Slice each sandwich diagonally if desired and serve immediately.