Tuna Melt Zucchini Boats are a quick and easy keto version of a sandwich classic. Made with canned tuna, green pepper, celery and parsley, they are topped with melted cheddar cheese and perfect for a no-fuss lunch, snack or dinner.

If you’re fond of tuna fish sandwiches but don’t want the bread, you will love these low-carb zucchini boats. I love coming up with new ways to utilize the abundant zucchini crop that comes every summer and stuffed zucchini is our family’s favorite way to enjoy summer squash.
While I usually stuff it with ground meat and marinara sauce, such as in my quick Low-Carb Italian Stuffed Zucchini Boats, or taco meat and black beans for “taco” zucchini, this version is faster and less time consuming to make.
Just whip up tuna salad with canned tuna, chopped up crunchy veggies, creamy mayo and tangy Dijon mustard, and top with some grated cheese, stuff the zucchini boats, bake for a couple minutes and your healthy dinner is on the table in no time!
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WHAT YOU WILL NEED

- Canned Tuna: pick good quality canned tuna in water. I like this pole and line caught wild tuna from Wild Planet.
- Mayo: use homemade or store bought avocado oil mayo for best results.
- Celery: to give the salad its classic flavor and crunch.
- Green Bell Pepper: for even more crunch! You can also use red or yellow bell pepper, if you prefer.
- Red Onion: white or yellow onion will also work, though I like red best in salads.
- Dijon Mustard: to add some tang and spiciness to the tuna salad.
- Parsley: to add some freshness and vitamin C.
- Grated Cheese: I use cheddar cheese for a classic tuna melt look but feel free to add any cheese good for melting that you like. Monterey Jack, Colby Jack, Havarti or your favorite blend will work just as well.
HOW TO MAKE KETO TUNA MELT ZUCCHINI BOATS
Step 1: Pre-bake the zucchini. Cut the squash lengthwise and scoop out most of the flesh and seeds. I find that a melon baller works best for this job. Your boats should be ¼- ½ inch thick.

Step 2: Make tuna salad. While the zucchini are cooking in the oven, chop up all the veggies and parsley, place them in a bowl, add canned drained tuna, mayo, Dijon mustard and mix together. Season with salt and pepper to taste.

Step 3: Stuff the zucchini. Scoop the tuna salad into the zucchini boats, top with grated cheese and bake or broil for a couple minutes until the cheese is melted and bubbly.


HOW TO SERVE TUNA MELT ZUCCHINI BOATS
Serve these low-carb tuna melts hot, at room temperature or cold. I like them either way! You can eat these on their own or with a side salad. If you serve the zucchini boats cold or at room temp, they can be cut into smaller pieces and enjoyed as finger food. Think mini finger sandwiches with no carbs!
STORAGE & MEAL PREP TIPS
For meal prep, bake the boats, let cool slightly, place in an airtight container and store in the fridge for up to 4 days. To serve, eat cold or reheat in the microwave for a minute or 2 until heated through.
FREQUENTLY ASKED QUESTIONS
CAN I ADD DIFFERENT VEGGIES TO TUNA SALAD?
Yes, absolutely. Make your tuna salad however you like, especially if you don’t have the ingredients in the recipe. As long as you have canned tuna, you are good to go!
Other veggies and herbs that will work in tuna salad:
- Red, orange or yellow bell pepper
- Poblano or cubanello pepper
- Jalapeno pepper for a spicy kick
- Finely diced carrot
- Scallions or green onions
- White or sweet onion
- Pickles
- Fresh herbs: dill, chives, tarragon or cilantro.
CAN I MAKE TUNA SALAD WITHOUT MAYO?
Yes. For a lighter version of tuna salad, use equal part Greek yogurt instead of mayonnaise. If you skip the mayo, you can squeeze in some lemon juice to add a bit of tang to the flavor. You can also mix 1 tablespoon of mayo and 1 tablespoon of Greek yogurt, if you don’t want as much mayo.
WHAT TO DO WITH SCOOPED OUT ZUCCHINI FLESH?
For this recipe, you will be removing some zucchini flesh and seeds to make the boats or “shells” but don’t discard it! My favorite way to use up extra zucchini goodness is to place the scooped out flesh in a zip lock bag, close it, flatten the zucchini with my hand and freeze flat (that way it won’t freeze in one clump). Then I add it frozen to smoothies for a neutral tasting veggie boost. You can also add it to soups or pasta sauce.

If you made these Tuna Melt Zucchini Boats or if you have any questions about this recipe, please leave me a comment below. I would love to hear from you!
OTHER TASTY LOW-CARB MEALS
- Buffalo Tuna Salad
- Egg Roll in a Bowl
- Spaghetti Squash with Bacon, Goat Cheese and Spinach Skillet
- Low-carb Avocado Egg Salad
- Caprese Chicken Sheet Pan

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Recipe

Keto Tuna Melt Zucchini Boats
Ingredients
- 2 medium zucchini
- 1 can tuna in water
- ⅓ cup green pepper diced small
- ¼ cup red onions diced small
- 1 celery rib diced small
- 2 tablespoons mayo
- 1 teaspoon Dijon mustard
- 2 tablespoons chopped parsley
- ⅓ cup grated cheddar cheese
- Salt & pepper to taste
Instructions
- Heat up the oven to 400 degrees Fahrenheit.
- Cut the zucchini in half lengthwise. Using a melon baller or a small spoon remove most of the seeds and flesh to make zucchini boats. I usually freeze the flesh in a zip lock bag and use in smoothies or soups.
- Place emptied zucchini boats on a baking tray and place in the preheated oven. Bake for 15-20 minutes until tender but not mushy.
- Make the tuna salad. In a medium bowl mix together tuna, green pepper, celery, red onions, parsley, mayo, mustard, salt and pepper.
- Stuff zucchini boats with tuna salad and top with grated cheese.
- Bake for 5-7 minutes in 410 degrees Fahrenheit or broil until the cheese is melted.
- Serve immediately.
Amy
OMG these were soooo good! I was looking for a bit of a fun appetiser when we had friends over and they were super popular. They finished it in seconds! Think I might try them with baby zucchini as well as they would be easy enough to pick up.
Freya
My boyfriend is currently following a keto diet and he absolutely loved this recipe…and I did too! It made a really nice change from having tuna in sandwiches too.
The Sudden Cook
These look and sound amazing! Canned tuna is a permanent fixture in my pantry and will certainly love to give these a go!
Jeri
What a great recipe! Such a perfect way to use up zucchini, and so healthy too! I will definitely be making this when my zucchini crop is ready!
Kim
I stopped at farmers market this weekend just so I could get some zucchini to make this recipe. Delicious! We had no leftovers and I'm going to have to put zucchini on this week's list too so I can make it again.
Tyanne
Super amazing snack to end the summer! I love finding new ways to use zucchini.
Andrea White
These boats are awesome! So flavorful and delicious!
Jean
the low-carb recipe got me, zucchini is delicious and healthy. I made it for dinner and planning to do again I want my friends to try this too.
Aya
This was so easy to make and absolutely delicious! My husband is a big fan of Tuna and loves eating it in sandwiches. So I decided to make this for a change and he loved it! Will definitely be making this again.
Agnieszka
So glad he liked it!