California Onigiri is a fun twist on the classic Japanese rice ball, inspired by the flavours of a California roll. The rice is mixed with tobiko (flying fish roe) for that little pop, then filled with a creamy crab mixture made with imitation crab, kewpie mayo, avocado and cucumber. Wrapped in crisp nori, these are perfect for an easy lunch, snack, or meal prep option.
It’s everything you love about a California roll, just in rice ball form!
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What is California Onigiri?
Onigiri, also known as omusubi, is a classic Japanese rice ball that’s been around for centuries. Traditionally, it’s made with rice shaped into triangles or rounds and filled with something salty or savoury, making it a simple, portable snack that’s still hugely popular across Japan today.
This version takes inspiration from the California roll, with a creamy filling of imitation crab, avocado and cucumber. Instead of rolling everything into sushi, it’s tucked inside seasoned rice and shaped into onigiri – so you get the same familiar flavours in a quicker, more approachable way. It’s easy to make at home, doesn’t require any special equipment, and once you get the hang of shaping the rice, it becomes something you’ll keep coming back to.
Why You’ll Love This Recipe
A different take on a Western-style sushi classic, you’ll want to come back to this onigiri again and again.
- California roll vibes, less effort – All the same flavours, no rolling required.
- Creamy, crunchy, savoury – A good mix of textures in every bite.
- Perfect for meal prep – Holds up well for lunches or snacks on the go.
- Beginner-friendly – No sushi-making skills needed!
- Customisable – Easy to tweak fillings based on what you have.
Ingredients & Substitutions
• Short grain rice – Use Japanese short-grain or sushi rice for the right sticky texture.
• Water – Standard ratio to cook the rice until soft and fluffy.
• Tobiko – Adds a light pop and briny flavour. Swap with masago or leave out if needed.
• Imitation crab sticks – Classic California roll filling. Can substitute with real crab.
• Kewpie mayonnaise – Rich and slightly tangy. Regular whole egg mayo works if needed.
• Avocado – Adds creaminess. Use ripe but still slightly firm.
• Continental cucumber – Fresh crunch. Lebanese cucumber works too.
• Nori sheets – For wrapping. Cut full sheets in half or use snack-size nori.
How to Make California Onigiri
Step 1: Rinse the rice under cool running water until the water runs mostly clear. Cook using a rice cooker, or on the stovetop by bringing the rice and water to a boil, then reducing to low, covering, and cooking until the water is absorbed. Set aside to cool slightly.
Step 2: Shred the crab sticks using a fork and mix with Kewpie mayonnaise until combined. Dice the avocado into small cubes. Do the same with the cucumber, removing the seeds first.
Step 3: Once the rice has cooled enough to handle, gently fold through the tobiko until evenly distributed.
Step 4: Using an onigiri mould or damp hands, add a layer of rice and press it down slightly to create a small well. Add the crab mixture, cucumber and avocado, then top with more rice and press firmly to shape.
Step 5: Remove from the mould. Cut the nori sheets in half and wrap around the onigiri. Keep the nori separate until ready to eat for best texture.
Tips for Perfect California Onigiri
- Use freshly cooked rice – Warm rice is easier to shape and holds together better than cold rice.
- Wet your hands or mould – Prevents the rice from sticking and makes shaping much easier.
- Don’t overfill – Too much filling will cause the onigiri to fall apart.
- Press firmly, not aggressively – Compact enough to hold shape, but not dense.
- Dice fillings small – Helps everything distribute evenly.
- Keep nori separate if storing – Wrap just before eating to keep it crisp.
- Use slightly firm avocado – Overripe avocado will turn mushy.
Variations
- Spicy California onigiri – Add sriracha or chilli oil to the crab mixture.
- Teriyaki chicken – Swap the filling for chopped teriyaki chicken and avocado.
- Tuna mayo – Use canned tuna mixed with Kewpie instead of crab.
- Salmon avocado – Fresh or cooked salmon works really well here.
- No tobiko – Skip it for a simpler version, or replace with sesame seeds.
Storage & Make-Ahead
- Best eaten fresh – Onigiri is at its best the day it’s made, while the rice is still soft.
- Refrigerate leftovers – Store in an airtight container for up to 24 hours. The rice will firm up slightly.
- Keep nori separate – Wrap just before eating to prevent it from going soggy.
- Avoid freezing – The filling doesn’t freeze well and the rice texture changes once thawed.
FAQs
Can I make California onigiri ahead of time?
Yes, but they’re best eaten fresh. If making ahead, store in the fridge and bring to room temperature before eating for the best texture.
Why is my onigiri falling apart?
Usually the rice is too cool, too dry, or not pressed firmly enough. Slightly warm, sticky rice works best.
Can I use regular rice instead of short grain rice?
You can, but it won’t hold together as well. Short-grain rice is much stickier and gives the best result.
What can I use instead of tobiko?
Masago is the closest substitute, or you can leave it out entirely.
Can I make this without an onigiri mould?
Yes, just use damp hands to shape the rice. It might not be as uniform, but it works just as well.
Can I use real crab instead of imitation crab?
Absolutely. It will give a slightly sweeter, more natural flavour.
More Onigiri & Rice Ball Recipes to Try
If you loved this California onigiri, here are a few more easy rice ball recipes to add to your rotation. Perfect for lunches, snacks, or meal prep.
- Tuna Mayo Rice Balls – A simple, classic filling that’s creamy, comforting and always a hit.
- Spam & Egg Rice Balls – A savoury, satisfying combo with crispy spam, fluffy egg and seasoned rice.
- Spicy Tuna Onigiri – Creamy, spicy tuna filling wrapped in soft rice with a hint of heat.
📖 Recipe
California Onigiri
Ingredients
Onigiri Rice
- 450 g short grain rice
- 560 g water
- 110 g tobiko
Filling
- 5 imitation crab sticks
- 2 tablespoon Kewpie mayonnaise
- ½ avocado
- ½ continental cucumber
- 6 sheets nori
Instructions
- Rinse rice under cool running water until water runs relatively clear. Add rice and water to a rice cooker and cook according to appliance instructions. Alternatively, use stove top method: add rice and water to a large sauce pan and place over high heat. When the water comes to a boil, reduce heat to the lowest setting, place a lid on top of the pot and allow rice to absorb for 12-15 minutes. Once cooked, remove from stove. Transfer rice to a bowl or lined baking tray to cool slightly before making onigiri.
- To prepare filling: use a fork to shred crab sticks and add to a bowl with Kewpie mayonnaise. Stir to combine. Dice avocado into cubes, approximately 0.5-0.7cm. Do the same with the cucumber, removing the seeds first.
- Once rice has cooled enough to handle, stir through tobiko until evenly dispersed through the rice. If using an onigiri mould, soak it in cool water between uses to stop the rice from sticking. Otherwise, onigiri can be formed using dampened hands.
- Using the moulds: add about one quarter cup of rice to the base of the mould, pressing it in and creating a small well in the centre to hold the filling. Add one tablespoon of crab meat and one teaspoon each of cubed cucumber and avocado. Add another quarter cup of rice over the top of the fillings. Add the lid of the mould and press down firmly to compact the rice.
- Pop out onigiri from the mould. Slice six sheets of nori in half. Place one half on a board on the rice ball on top, in the centre. Fold nori around the rice. Nori will soften once wrapped around the rice ball. You can leave the nori separate until ready to eat to retain crispiness.
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