7-Ingredient Watermelon Vegan Tuna with Spicy Mayo Sauce

7-Ingredient Watermelon Vegan Tuna with Spicy Mayo Sauce

Let me tell you a little bit about the inspiration behind this recipe. I first came across this concept of “vegan fish” made out of watermelons in a vegan Facebook group and I was so intrigued because I had never heard of anything like it. 

After a bit of research, I realized it was actually a thing and bloggers like @edgyveg had created variations of it in the past.⠀

So I decided to create my own, poke bowl friendly, 7 ingredient Watermelon Vegan Tuna with Spicy Mayo Sauce 🌶 All you need is a watermelon, seaweed, tamari, rice vinegar, sesame oil, vegan mayo & sriracha!⠀

I am telling you guys, this recipe makes for a super juicy, salty and melt in your mouth vegan tuna alternative! You must try it!⠀

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7-Ingredient Watermelon Vegan Tuna with Spicy Mayo Sauce

7-Ingredient Watermelon Vegan Tuna with Spicy Mayo Sauce

5 from 5 votes
Prep Time: 10 minutes
Cook Time: 2 hours 5 minutes
Total Time: 1 day
Keyword: Recipe, Vegan


  • 700 grams of watermelon seeds and rind removed and diced into 2cm x 2cm cubes
  • 1 tsp ground seaweed or seaweed flakes
  • 4 tbsp tamari *
  • 4 tbsp white rice vinegar
  • 2 tsp sesame oil

Spicy Mayo



  • In a large airtight container, add watermelon, seaweed, tamari, white rice vinegar and sesame oil. Put on the lid and shake gently to distribute the seasonings.
  • Place in the fridge for 2 hours.
  • After 2 hours, preheat oven to 250ºF and line a baking sheet with parchment paper.
  • Place all the cubes on the parchment paper. Reserve the sauce to use in another recipe such as an Asian sauté or a pad thai.
  • Bake for 2 hours, flipping the cubes halfway through.
  • After 2 hours, increase oven temperature to 350ºF and bake for 5 more minutes, until slightly charred.
  • Transfer into an airtight container, close and place in the fridge until cold.
  • Once cold, and right before serving, mix vegan mayo and sriracha together and add into the container with your watermelon. Toss to coat.
  • Serve immediately in vegan sushi, in a vegan poké bowl or even as a garnish on an avocado toast.


* Feel free to substitute tamari with soy sauce.

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