Name: Tuna Salad Croissant Sandwich
Prep time: 15 min
Total time: 15 min
Ingredients: 2 cans tuna packed in olive oil (drained); ½ cup celery (diced, 1-2 celery stalks); 1 small shallot (minced); 2 tbsp fresh dill (chopped); 2 tsp capers; 1 tsp lemon zest; 1 tbsp freshly squeezed lemon juice; 1 tsp dijon mustard (or to taste); ½ cup kewpie mayo (or regular mayo); kosher salt (to taste); freshly ground black pepper (to taste); 4-8 butter or romaine lettuce leaves; 4 croissants (sliced in half lengthwise); 1-2 tomatoes (thinly sliced); 1 cup sprouts (alfalfa, broccoli, radish, or a mix); cornichons (optional)

Jump to Recipe Jump to Video

Tuna Salad Croissant Sandwich will satisfy your lunch cravings in just a few easy steps! Packed with flavor and texture, this refreshing recipe combines creamy, tangy tuna salad with layers of veggies, all nestled in a rich, buttery croissant.

Tuna salad croissant sandwich with sprouts, tomato, lettuce, and cornichons.

We love to add a little gourmet flair to classic dishes. In this recipe, a buttery croissant cradles our signature tuna salad for a uniquely flavorful lunch. The best part is it takes just 15 minutes to enjoy these elevated flavors!

Looking for other delicious sandwich recipes? Try our chicken salad croissant sandwich, Japanese egg salad sandwich, mortadella and burrata panino, or our slow cooker bbq chicken sandwich.

Jump to:

Why You'll Love This Tuna Sandwich Recipe
Key Ingredients
Substitutions and Variations
How to Make a Tuna Sandwich
Tuna Sandwich Tips
Related Recipes
Did You Like This Recipe?
📖 Recipe

Why You'll Love This Tuna Sandwich Recipe

Taste - The combination of tangy tuna salad, butter lettuce, and buttery croissant makes a delicious bite.
Texture - The tuna salad is tender and creamy, the butter lettuce is crunchy, and the croissant is flaky.
Effort - All you need to do is mix the tuna salad with the other ingredients then add it to the lettuce and croissant.
Time - It takes about 15 minutes to make the tuna salad and assemble the sandwich.

Key Ingredients

Ingredients for tuna sandwich, canned tuna, shallot, dill, kewpie mayo, lemon zest and juice, dijon mustard, celery, capers, pepper, croissant, tomato, sprouts, cornichons.

Tuna packed in olive oil - Tuna packed in olive oil is richer than other canned tuna, but regular tuna in water is fine too. Just remember to drain well.
Celery - Celery adds a light crunch.
Shallot - Shallot add a subtle onion flavor and sharpness.
Fresh dill - Fresh dill is bright and herbaceous.
Capers - Capers supply briny goodness.
Lemon juice and zest - Lemon juice and zest brighten up the sandwich.
Dijon mustard - Dijon mustard gives the salad some tang.
Kewpie or regular mayonnaise - We prefer kewpie mayo for its rich umami flavor.
Croissant - Croissants are a buttery and flaky vehicle for the tuna salad.
Lettuce - The butter lettuce or romaine is crisp and refreshing.
Tomatoes - Thinly sliced tomatoes add a sweet umami flavor to medley.
Sprouts - Use alfalfa, broccoli, radish, or a mix! They add a tasty crunch to the sandwich.
Cornichons - Add a side of cornichons or pickles for a delicious briny addition!

See recipe card for quantities.

Substitutions and Variations

Lettuce wrap - For a low-carb and gluten-free option, enjoy it without bread as a tuna lettuce wrap.
Bread - This sandwich will also be delicious on on ciabatta, sourdough, or your favorite baguette.
Mini croissants - Use mini croissants to make small tea sandwiches for kids and parties. They make a great appetizer!
Spicy - Substitute Kewpie mayo with spicy Kewpie mayo for a touch of heat!

How to Make a Tuna Sandwich

Steps to make croissant tuna sandwich, break up tuna and mix flaky tuna, kewpie mayo, celery, shallot, dill, capers, lemon zest and juice.

Make tuna salad - Add the tuna to a large mixing bowl and use a fork to break up the fish into small flaky pieces. Then add the diced celery, minced shallot, chopped dill, capers, lemon zest and juice, dijon mustard, and mayonnaise to the tuna. Fold the ingredients together until combined. Then season with salt and pepper to taste. (Photo 1, 2, 3, and 4)

Steps to make croissant tuna sandwich, layer lettuce, sliced tomato, tuna salad, and sprouts on croissant, then add croissant top and cornichons on toothpick.

Assemble sandwich - Lay the croissant bottoms cut side up on a serving plate and top with 1-2 slices of lettuce and sliced tomatoes. Layer a scoop of tuna salad on top of the tomatoes and spread it out evenly, then sprinkle sprouts on top. Place the croissant tops on each sandwich and gently press down. (Photo 5 and 6)
Add cornichons and serve - If desired, put a couple of cornichons on toothpicks and place through the top of the sandwich to hold it in place. Serve and enjoy! (Photo 7 and 8)

Tuna Sandwich Tips

Lightly toast the croissant for a little crispiness. Just make sure to only toast it briefly because it can burn easily.
Don't overstuff the sandwich or the tuna salad will fall out when you press the bread together while eating it.

Hands holding healthy tuna croissant sandwich with sprouts, tomato, lettuce, and cornichons.

Did You Like This Recipe?

Love this easy tuna sandwich recipe? Please leave a 5-star rating in the recipe card & leave a comment below. Thanks!

Sign up for THP's newsletter and keep in touch on Instagram, Facebook, Pinterest, TikTok, and YouTube. If you make this recipe, tag #theheirloompantry so we can see your homemade tuna sandwich!