Easy Vegan Tuna Sushi Slice

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Craving sushi but don’t have the time (or patience) to roll it up perfectly? Because same. This easy vegan tuna sushi slice is the answer. It’s got all the fresh, vibrant flavours of your favourite sushi roll, layered up in a way that’s simple, fuss-free, and perfect for sharing. Think of it like sushi made easy – no fancy skills needed, just tasty, wholesome ingredients that come together in a crowd-pleasing slice. Ideal for lunch, dinner, or even to take along to a picnic, it’s a fun twist on a classic that’ll have everyone coming back for seconds.

Why you will love this recipe

• It’s completely plant-based – the “tuna” topping is made with simple vegan ingredients that still give you that sushi vibe without the fish.
• No rolling required – just layer it up, slice, and serve. Way easier than traditional sushi but just as delicious.
• Packed with flavour and texture – creamy avocado, tangy pickled veggies, seasoned rice, and that savoury vegan tuna on top.
• Perfect for sharing – slice it into squares and you’ve got the ultimate platter for parties, picnics, or a quick weeknight dinner.
• Meal-prep friendly – it keeps well in the fridge, so you can enjoy sushi-style goodness anytime.
  
  

What ingredients you will need to make this recipe

• Sushi rice – the preferred rice to use so it holds together as a slice.
• Rice wine vinegar – to season the rice with for that classic tang.
• Sesame oil – this adds a beautiful toasted flavour to the sushi slice.
• Avocado – creamy and fresh, a must in any sushi-inspired dish.
• Cucumber ribbons – add crunch, freshness and colour.
• Chickpeas & heart of palm – the base of our vegan “tuna” mix.
• Old Bay Seasoning – this specific spice blend gives the tuna that seafood-like flavour.
• Vegan mayo or kewpie – for creaminess in the topping and a drizzle over the top of the slice.
• Soy sauce or tamari – adds that umami kick to dip your slice into.
• Nori sheets – for that ocean flavour and perfect to eat the sushi slice with.
• Sriracha sauce – for an extra kick if you like a traditional ‘spicy tuna’ sushi.
• Pickled ginger, sesame seeds & spring onion – optional, but these toppings take it to the next level.

Step-by-step how to make this recipe

Step 1: Cook and season the rice

Start by cooking your sushi rice. Rinse about two cups of rice under cold water until the water runs mostly clear, then cook it with two and a quarter cups of water either on the stovetop or in a rice cooker. Once it’s done, let it rest for ten minutes off the heat. In a small bowl, stir together rice vinegar and a pinch of salt until it dissolves, then fold this seasoning gently through the rice. Spread it out into a wide bowl and let it cool to room temperature – if you’re in a hurry, you can fan it to speed things up. Be gentle here, you want fluffy grains, not mush.

Step 2: Form the slice

Next, line a slice tin with baking paper, leaving some overhang so it’s easy to lift out later. Lightly oil the paper to stop anything from sticking. Once your rice has cooled, dampen your hands or a spatula with a little vinegar water and press the rice firmly and evenly into the tin. Aim for a layer about two to two and a half centimetres thick. If you like that classic sushi flavour, you can lay a sheet or two of nori over the rice before adding the topping, but totally up to you!

Step 3: Make the vegan “tuna”

Now it’s time to make the vegan tuna. In a bowl, roughly mash one can of drained chickpeas and one can of drained hearts of palm until they resemble flakes. Stir through vegan mayonnaise, salt, soy sauce or tamari, a sprinkle of old bay seasoning, and if you like, a dash of sesame oil. For that extra ocean flavour, shred up a sheet of nori or use furikake seasoning. Taste and adjust as you go – add more mayo if you want it creamier, more soy for savouriness, or a little sriracha if you’re after some heat. The mix should be moist and creamy but not sloppy.

Step 4: Prepare the veggies/toppings

Because we are working with a slice, you are going to want to keep the toppings thin and relatively even. For this part, you will need to use a sharp knife, mandoline slicer or peeler to create ribbons from the cucumbers. For the avocado, it’s best to use a sharp knife to thinly slice. You will also want to prepare the optional toppings at this point too.

Step 5: Layer your sushi slice

Spread the vegan tuna mixture evenly over your rice (or over the nori if you used it), pressing it down lightly so it sticks. On top of that, layer your avocado slices and cucumber ribbons – just make sure they’re patted dry first so your slice doesn’t get watery. To finish, scatter sesame seeds, extra spring onion and, if you’re feeling fancy, a drizzle of spicy mayo made by mixing sriracha with vegan mayo. Pop the whole thing in the fridge for about twenty to thirty minutes to set, which makes it much easier to slice neatly.

Step 6: Serve

When you’re ready to serve, use the baking paper to lift the slice out of the tin. Grab a sharp knife, dampen the blade, and cut into squares, wiping the knife or oiling the knife between cuts for clean edges. Serve it with pickled ginger, a splash of soy or tamari, and even a dab of wasabi if that’s your vibe.

Tips for perfecting this recipe

• The rice is the heart of good sushi, so don’t skip rinsing it properly before cooking – this removes excess starch and keeps it fluffy instead of gummy. Once it’s cooked, take the time to season and cool it; hot rice will make your toppings soggy and won’t slice as neatly.
• When pressing the rice into the tin, dampen your hands with a little vinegar water or sesame oil so it doesn’t stick, and pack it down firmly enough that it holds together, but not so hard that it becomes dense. A sheet of nori under the topping adds great flavour and makes it feel more like classic sushi, but it’s totally optional.
• For the vegan tuna, mash the chickpeas and hearts of palm just enough to create a flaky texture. You don’t want a paste – the little chunks give it that “tuna” feel. Taste as you go and adjust the balance of mayo, soy, vinegar and spice until it’s exactly how you like it.
• Pat your avocado and cucumber slices dry before layering them on top, otherwise the slice can end up watery. Once everything is assembled, a short chill in the fridge really helps it firm up, so you’ll get those clean, sharp edges when you cut it.
• Use a sharp knife dipped in water to slice, wiping it between cuts to keep each square neat. A sprinkle of sesame seeds, a drizzle of spicy mayo and a handful of spring onions at the end make it look and taste extra special.

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