These High-Protein Tuna Avocado Zucchini Tacos are a fresh, low-carb lunch with cheesy zucchini taco shells and a creamy tuna avocado filling. Each serving has about 30 grams of protein, and they’re naturally gluten-free, filling, and easy enough for lunch or a light dinner.
I’ve been having so much fun experimenting with zucchini lately. After making my zucchini wraps, I wanted to try something a little different: tuna avocado zucchini tacos with cheesy homemade shells.
The shells start with a little Parmesan on parchment paper, followed by overlapping zucchini slices and shredded mozzarella. Everything bakes together until golden around the edges. Give them a few minutes to cool, and they’re ready to lift and fold around the filling.
For the filling, I wanted something creamy without using mayonnaise. Mashed avocado and a little Greek yogurt bring the tuna and chopped hard-boiled eggs together, while lemon juice, red onion, and fresh dill add flavor and a little crunch.
You can mix the filling while the shells bake, so there’s no need to prepare everything separately. Fill them just before eating to keep the shells from getting soggy, and lunch is ready.
Why You’ll Love These Tuna Avocado Zucchini Tacos
- Cheesy homemade shells: Thin zucchini slices bake together with mozzarella and Parmesan, with no flour needed.
- Creamy tuna filling: Avocado, chopped eggs, and Greek yogurt give the filling texture, while lemon and dill add freshness.
- Prepare the filling while the shells bake: The oven time gives you a chance to finish the rest of the recipe.
- Three individual tacos: Divide the filling evenly so each taco gets a little of everything.
Ingredients You’ll Need
For the Zucchini Taco Shells
Zucchini – Choose one large, fairly straight zucchini so it’s easy to cut into even slices. Thin slices soften quickly in the oven and overlap more neatly than thick ones.
Mozzarella cheese: Use shredded low-moisture mozzarella. It melts over the overlapping zucchini slices and helps hold the shells together. Fresh mozzarella contains more moisture and can make the shells wetter.
Parmesan cheese: Parmesan adds a savory flavor and helps the bottoms of the shells brown. Use parchment paper and let the shells cool briefly before lifting them, since the melted cheese is very soft straight from the oven.
Salt and Black Pepper – A small amount is all you need to season the zucchini before baking.
For the Tuna Avocado Filling
Tuna – Drain the tuna thoroughly so the filling doesn’t become watery. Tuna packed in water or olive oil can both be used.
Hard-Boiled Eggs – Eggs add even more protein and give the filling a heartier texture. Chop them before adding if you prefer a chunkier filling.
Avocado – Use a ripe avocado that gives slightly when pressed. It should be soft enough to mash but not overly brown or watery.
Greek Yogurt – Greek yogurt brings everything together and adds creaminess without making the filling too rich.
Red Onion – Finely chopped red onion adds crunch and a sharper flavor. Chop it quite small so you don’t get large pieces in each bite.
Fresh Dill – Dill pairs especially well with tuna, eggs, lemon, and yogurt. Fresh dill gives the filling the best flavor, but a smaller amount of dried dill can work if needed.
Fresh Lemon Juice – Lemon juice brightens the filling and helps balance the richness of the avocado, eggs, and cheese.
Salt and Black Pepper – Season the filling after mashing, then taste and adjust as needed.
How to Make Tuna Avocado Zucchini Tacos
Prepare the Parmesan Bases
Preheat the oven to 350°F or 175°C. Line a large baking sheet with parchment paper.
Divide the ¼ cup of shredded Parmesan into three small circles on the parchment paper, leaving room around each one for the zucchini slices. The zucchini will extend beyond the Parmesan as you arrange the overlapping slices.
The Parmesan bases should be about the size you want your finished taco shells to be.
Slice and Arrange the Zucchini
Cut the zucchini into very thin, evenly sized slices. A mandoline makes this easy, but a sharp knife will work too.
Arrange the slices over each Parmesan circle, slightly overlapping them to create three round shells.
Make sure the slices overlap well through the center. This helps the finished shells stay together when you lift and fold them.
Add the Cheese
Season the zucchini evenly with salt and black pepper.
Divide the shredded mozzarella between the shells, spreading it over most of the zucchini.
Try to cover the overlapping areas with cheese because this is what helps bind the zucchini slices together.
Bake the Taco Shells
Bake for 18 to 20 minutes, or until the cheese is completely melted and golden around the edges.
Remove the baking sheet from the oven and leave the shells to cool for about five minutes.
They will be very soft when they first come out, but the cheese firms up as it cools, making the shells much easier to lift and fold.
Make the Tuna Avocado Filling
While the shells bake, add the drained tuna, hard-boiled eggs, avocado, Greek yogurt, red onion, fresh dill, and lemon juice to a medium bowl.
Mash everything together with a fork until well combined.
You can leave a few pieces of egg and avocado visible for a chunkier filling or continue mashing until it becomes smoother and creamier.
Season with salt and black pepper. Taste and add a little more lemon juice or salt if needed.
Assemble the Zucchini Tacos
Use a thin spatula to carefully loosen each shell from the parchment paper.
Divide the tuna avocado filling evenly between the three shells, placing it on one side of each one.
Gently fold the empty side over the filling to create a taco shape. Serve immediately while the shells are still warm and flexible.
My Best Tips
Use a mandoline when possible. Evenly sliced zucchini cooks at the same rate and creates shells that are easier to fold.
Don’t leave gaps between the slices. Overlap the zucchini through the middle and around the edges so the shells don’t separate when lifted.
Give the shells time to cool. Five minutes makes a big difference. If you try to move them straight from the oven, they may be too soft and tear.
Drain the tuna well. Too much liquid can make the filling loose and may cause the finished tacos to become soggy.
Easy Variations
Prefer a filling without avocado? Try my tuna salad, made with Greek yogurt, a little mayonnaise, celery, and pickles. Spoon it into the zucchini shells just before serving.
Salmon Avocado Tacos – Replace the tuna with the same amount of drained canned salmon.
Chicken Salad Tacos – Use finely shredded cooked chicken instead of tuna.
Spicy Tuna Tacos – Add chopped jalapeño, red pepper flakes, or a drizzle of hot sauce to the filling.
Extra Crunch – Stir in finely diced cucumber or celery.
Mayonnaise Version – Replace the Greek yogurt with the same amount of mayonnaise for a richer filling.
Storage
These tacos are best assembled just before serving. The tuna avocado filling will gradually soften the zucchini shells if they sit together for too long.
Store leftover shells and filling separately in airtight containers in the refrigerator. The zucchini shells will keep for up to two days, while the filling is best enjoyed within one day because the avocado may begin to darken.
To reheat the shells, place them in the oven or air fryer for a few minutes, just until warm and flexible. Let them cool briefly before filling.
I don’t recommend freezing the assembled tacos. Zucchini and avocado can both release water and change texture after thawing.
Frequently Asked Questions
Why are my zucchini shells falling apart?
Let them cool for about 5 minutes before lifting with a thin spatula. Overlap the zucchini slices without gaps and spread the mozzarella across the overlaps so everything holds together.
Why are the shells soggy?
Thick zucchini slices, too many layers, or fresh mozzarella can add excess moisture. Use thin slices and low-moisture mozzarella. The finished shells should be soft and foldable, with golden edges.
How do I keep the tuna filling from getting watery?
Drain the tuna well, use thick Greek yogurt, and let the boiled eggs cool before mixing. Stick to the listed amounts of yogurt and lemon juice before adding more.
More Zucchini Recipes
For another handheld meal, try my zucchini sliders, with zucchini slices taking the place of burger buns.
If you’re looking for a baked dinner, these ground beef stuffed zucchini boats have a hearty meat filling and melted cheese. Or try my creamy zucchini Alfredo noodles when you’re in the mood for zucchini with a rich Parmesan sauce.
High Protein Tuna Avocado Zucchini Tacos
Description
Ingredients
For the Zucchini Taco Shells
- 1 large zucchini
- 1 cup mozzarella cheese shredded, about 4 oz or 115g
- 1/4 cup parmesan cheese shredded
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
For the Tuna Avocado Filling
- 1 can tuna drained, about 5 oz or 140g
- 2 hard-boiled eggs large
- 1 ripe avocado
- 1 tablespoon plain Greek yogurt
- 1 red onion small, finely chopped
- 2 tablespoons fresh dill chopped
- 1 tablespoon fresh lemon juice
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
Instructions
- Prepare the baking sheet. Preheat the oven to 350°F (175°C). Line a large baking sheet with parchment paper.
- Slice the zucchini. Using a mandoline or sharp knife, cut the zucchini into very thin, even rounds. Pat away any visible surface moisture with a paper towel.
- Add the Parmesan. Divide the Parmesan into 6 small, evenly spaced circles on the parchment paper. Leave enough room around each one to build a zucchini shell.
- Arrange the zucchini. Place the zucchini slices over each Parmesan circle, overlapping them around the outside like flower petals. Add a slice in the center to cover the opening. Keep the slices overlapping so each shell forms one continuous round without gaps.
- Add the mozzarella. Season the zucchini with salt and pepper. Divide the mozzarella evenly over the three rounds, spreading it across the overlapping slices to help hold them together.
- Bake. Bake for 18–20 minutes, until the zucchini is tender and the cheese is melted and golden around the edges.
- Make the filling. While the shells bake, combine the drained tuna, eggs, avocado, Greek yogurt, red onion, dill, lemon juice, salt, and pepper in a bowl. Mix with a fork, gently mashing the avocado until the filling is as chunky or creamy as you like.
- Let the shells cool. Remove the baking sheet from the oven and let the shells rest for about 5 minutes. They should be firm enough to lift from the parchment but still flexible enough to fold. Carefully loosen each one with a thin spatula.
- Fill and fold. Divide the filling evenly between the three shells, placing it on one half of each round. Gently fold the other half over the filling and serve immediately.
Notes
Nutrition information is shared to make meal planning easier. Values are estimates and can vary depending on the ingredients, brands, and serving sizes used. Learn more in my nutrition policy.
