If you’ve been wanting to try the viral sushi nigiri ice cube tray hack, this vegan tomato “tuna” version is such a fun place to start. It looks incredibly impressive, but it’s surprisingly simple to make. Marinated tomatoes take on a soft, silky texture and rich umami flavour that makes them a delicious plant-based alternative to tuna, paired with sushi rice. They’re perfect for party platters, lunchboxes or a fun weekend cooking project.

One of my favourite parts of this recipe is using silicone moulds (ours are from seed and sprout – we used 2 of the 12 hole trays that are 25ml sizes) instead of a standard ice cube tray. They make shaping the nigiri so much easier, release effortlessly without needing cling wrap, and are a reusable alternative that cuts down on single-use plastic. If you’ve seen the viral hack online, this is an even easier way to recreate it at home.

Roma tomatoes are naturally firm and hold their shape beautifully after marinating, while the combination of soy sauce, miso and nori creates that savoury, ocean-inspired flavour. The result is a simple recipe that looks impressive, tastes delicious and is always a talking point when served.

These bite-sized nigiri are suitable for the whole family from 18+ months. For younger children around 18 months and over, I recommend cutting each nigiri in half before serving to create a more manageable size. As always, supervise young children while they eat and adjust serving sizes to suit your child’s age and eating abilities.

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Vegan Tomato "Tuna" Nigiri

Prep Time 5

Cook Time 22

Total Time 27

Servings 3

Suitable For 18+ months

Metric - US Customary Units

Ingredients

Tomato “Tuna”

3 Roma tomatoes
2 tbsp soy sauce (low salt)
1 tbsp rice wine vinegar
1 tsp white miso paste
1/2 tsp smoked paprika
1 tbsp water
1/2 sheet nori (finely chopped)

Sushi Rice

200 g uncooked sushi rice
375 ml water
2 tbsp rice vinegar
1 tbsp raw sugar
1/2 tsp sea salt

Instructions

Lightly score a small X into the base of each tomato, then place in a small pot and cover with boiling water from the kettle, then bring back to the boil on the stove on high heat for 40-60 seconds, or until the skin starts to lift. Transfer immediately to ice cold water to stop the cooking.
Peel away the skins, then cut each tomato into quarters. Gently scoop out the seeds and soft centre using a spoon, leaving just the tomato “cheeks”.
In a jar/bowl with a lid, whisk together the soy sauce, rice wine vinegar, miso paste, smoked paprika, water and nori, then add the tomato pieces, place your lid on and gently shake to coat. Cover and refrigerate for at least 4 hours, or overnight for the best flavour.
To make the sushi rice, rinse the rice under cold water until the water runs clear. Add the rice and water to a saucepan and bring to the boil. Reduce the heat to low, cover and cook for 12 minutes. Remove from the heat and leave, covered, for a further 10 minutes.
Stir the rice vinegar, raw sugar and sea salt through the hot rice using a spatula until combined. Transfer to a large tray or dish and allow to cool, gently turning the rice as it cools.
Lightly spray two 12-hole, 25ml silicone moulds (or an ice cube tray) with oil. Place one marinated tomato piece into each cavity. We also made avocado and pickled carrot nigiri in the remaining cavities, so if you’d like all 24 pieces to be tomato, simply double the tomato marinade.
Spoon the cooled sushi rice over the tomatoes, pressing down firmly so the rice is tightly packed. Tip: use the back of a flat container lid or spatula to create neat, compact nigiri. Leave to firm up for 30 minutes in the fridge until ready
Carefully flip the silicone mould, using a chopping board to supprt, and turn/press out the nigiri. Serve immediately or refrigerate until ready to eat (cut each piece in half for serving to kids under 3 years).