The Viral Spicy Tuna Crispy Rice Sandwich (Onigirazu)

If you have spent any time on food TikTok or Instagram lately, you have likely seen the obsession with “crispy rice.” Usually served as bite-sized appetizers at high-end spots like Nobu, the concept is simple but addictive: crispy, golden-fried sushi rice topped with spicy tuna. But why stop at an appetizer? Enter the Spicy Tuna Crispy Rice Sandwich—also known in Japan as a variation of Onigirazu.

This dish takes the best textures of the culinary world and smashes them together. You get the satisfying crunch of pan-seared rice patties (acting as the “buns”), the cool, creamy richness of fresh avocado, and the heat of spicy tuna tartare. It is savory, texturally complex, and surprisingly easy to make at home. It’s essentially a deconstructed sushi roll that you can hold in your hands.

Whether you are looking for a fun lunch, a protein-packed post-workout meal, or just something to impress your friends with, this recipe delivers on all fronts. The best part? You don’t need a deep fryer. A simple pan-sear creates that signature golden crust that holds the whole sandwich together.

Why This Recipe Works

Texture Heaven: The magic here lies in the contrast. The rice is seasoned with vinegar and sugar, pressed firmly, and then seared in oil. This creates a barrier that is crunchy and chewy on the outside, but remains soft and sticky on the inside. When you bite through that warm crust into the cold, creamy spicy tuna, it is a sensory experience unlike any other.

Customizable: Not a fan of raw fish? You can swap the tuna for cooked shrimp, imitation crab (surimi), or even teriyaki chicken. For a vegetarian option, crispy tofu or spicy mushrooms work beautifully. The “rice bun” is a blank canvas for whatever flavors you crave.

No Sushi Mat Needed: One of the biggest barriers to making sushi at home is the rolling process. It takes practice to get a tight roll. With this sandwich method (Onigirazu style), you simply layer ingredients and wrap it in plastic wrap. It is incredibly forgiving and much faster than rolling individual maki.

Ingredients

To make this restaurant-quality dish, you will need a few specific Japanese staples, most of which are available at standard grocery stores.

For the Crispy Rice “Buns”

• Sushi Rice – 2 cups (uncooked). You must use short-grain white rice (often labeled as Calrose or Sushi rice). Long-grain rice like Jasmine or Basmati will not stick together and your sandwich will fall apart.
• Rice Vinegar – 1/3 cup. Provides that classic tang.
• Granulated Sugar – 2 tablespoons. Balances the vinegar.
• Salt – 1 teaspoon.
• Neutral Oil – For frying (canola, vegetable, or grapeseed oil work best).
• Sesame Oil – 1 teaspoon (optional, for brushing on the rice for extra flavor).

For the Spicy Tuna Filling

• Sashimi-Grade Tuna – 1/2 lb (225g). Ensure you buy this from a reputable fishmonger or the frozen sushi section of an Asian market. It must be safe to eat raw.
• Kewpie Mayonnaise – 2 tablespoons. Japanese mayo is richer and creamier than American mayo (thanks to egg yolks and MSG). It makes a huge difference.
• Sriracha – 1 to 2 tablespoons. Adjust based on your spice tolerance.
• Soy Sauce – 1 teaspoon.
• Sesame Oil – 1/2 teaspoon.
• Green Onions – 2 stalks, finely chopped.
• Avocado – 1 large, sliced thin.
• Furikake or Sesame Seeds – For garnish (optional).

Instructions

Follow these steps to ensure your rice holds its shape and gets that perfect golden crust.

1. Wash and Cook the Rice: Rinse your sushi rice under cold water until the water runs clear. This removes excess starch. Cook the rice according to package instructions (or use a rice cooker).
2. Season the Rice: While the rice is still hot, mix the rice vinegar, sugar, and salt in a small bowl until dissolved. Pour this over the hot rice and gently fold it in using a wooden paddle or spatula. Fan the rice to cool it down to room temperature.
3. Shape the Patties: This is the crucial step. Line a baking sheet or cutting board with plastic wrap. Wet your hands with water (to prevent sticking) and grab a handful of rice. Form it into a square or round patty, about 3/4 inch thick. Pack it tightly. You want it dense so it doesn’t crumble in the pan. Place the patties on the plastic wrap and let them sit for 10-15 minutes to firm up.
4. Make the Spicy Tuna: finely mince your tuna steak until it resembles a tartare. In a bowl, mix the minced tuna with Kewpie mayo, Sriracha, soy sauce, sesame oil, and half of the green onions. Stir until combined.
5. Sear the Rice: Heat a generous amount of neutral oil in a non-stick skillet over medium-high heat. Carefully place the rice patties into the pan. Fry for 3-5 minutes per side, or until they are deep golden brown and crispy. If they are browning too fast, lower the heat. Remove and let them drain on a wire rack or paper towel.
6. Assemble: Place a square of plastic wrap on your counter. Place one crispy rice patty in the center. Top with sliced avocado and a generous mound of spicy tuna. Sprinkle with the remaining green onions. Place the second rice patty on top.
7. Wrap and Cut: Pull the corners of the plastic wrap up tightly around the sandwich, sealing it like a package. This pressure helps bind the ingredients. Using a very sharp knife (wet the blade slightly), cut the sandwich in half through the plastic wrap. Peel back the plastic to eat.

Tips for Success

The “Sticky” Factor: Do not skip the rinsing of the rice, but also don’t use “minute rice.” You need the natural starches of short-grain rice to act as the glue. If your patties are falling apart, you likely didn’t compress them enough or the rice was too dry.

Sashimi Safety: If you cannot find sashimi-grade fish, do not risk it with regular supermarket steaks. Instead, use canned tuna (mixed with the same spicy mayo sauce) for a budget-friendly version, or use poached shrimp chopped into small pieces.

Temperature Control: When frying the rice, don’t overcrowd the pan. If the oil temperature drops too much, the rice will absorb the oil and become greasy rather than crispy. Fry in batches if necessary.

Variations to Try

• The “Cali” Style: Swap tuna for imitation crab mixed with mayo, cucumber slices, and avocado.
• Truffle Salmon: Use fresh salmon instead of tuna and add a drop of truffle oil to the mixture.
• Vegetarian Crunch: Use marinated crispy tofu slices and top with kimchi for a Korean fusion twist.

Serving Suggestions

This sandwich is rich, so it pairs well with lighter sides. A simple Miso soup is the perfect accompaniment to wash down the crispy rice. You can also serve it with a side of Edamame (steamed soybeans) with sea salt, or a refreshing Japanese cucumber salad (Sunomono) to cut through the oil.

Cultural Context: What is Onigirazu?

While “crispy rice” is a modern Western fusion trend popularized by chefs like Nobu Matsuhisa, the sandwich format is inspired by Onigirazu. Originating from a Japanese manga series in the 1990s, Onigirazu is a “sushi sandwich” that doesn’t need to be shaped like a traditional triangular Onigiri ball. It became a massive trend in Japan because it allows for more fillings and is easier to pack in a bento box. This recipe marries that practical home-cooking method with the high-end texture of crispy rice.

Enjoy this crunchy, creamy, spicy delight immediately after cutting for the best texture!