Rinse sushi rice until the water runs clear. Soak for 20 minutes.

Prepare the sushi seasoning by mixing together rice vinegar, sugar, salt, and mirin. Optionally add a kombu sheet and heat over medium, stirring until dissolved.

Once the rice is done soaking, empty out the water and refill with equal parts water to rice. Bring to a boil, cover, and simmer on low for 17 minutes. When the rice is done cooking, take off the heat but do not remove the lid for another 10 minutes.

Add 2/3 of the sushi seasoning to the rice, folding it until thoroughly incorporated.

Line a pyrex (or any rectangular dish) with plastic wrap. Add the rice into there and press it in to get a uniform layer. Pack it tightly to form a solid block. The rice should be an even, 1 inch thick layer. Lay more plastic wrap on top, give the rice a final packing, and let sit in the fridge for at least 4 hours.

When ready to fry, wet a knife with water and cut the rice into desired size. Fry rice in batches at 375ºF until golden brown and crispy all over.

For the spicy mayo

Mix Japanese mayo, gochujang, sriracha, and toasted sesame oil.

Chop up tuna to desired size, mix with desired amount of spicy mayo, and thinly sliced scallion. Season with soy sauce to taste.

Serve the spicy tuna on top of the crispy rice and enjoy!