Based on the classic dish known as kayaku gohan, this all-shrimp version might remind you of paella, but with a different technique. It's even better if you start by making dashi, which only takes 15 minutes. Other protein you can use: squid (rings and tentacles); any thick fish fillets, salmon fillets or steaks, or virtually any combination of seafood; sliced boneless chicken thighs.
Put the oil in a large pot over medium-high heat. When it's hot, add the mushrooms and onion, and cook, stirring occasionally, until they're soft and brown in places, about 10 minutes.
Reduce the heat to medium and add the soaked kombu reserved from the dashi if desired and the rice; stir to combine. Add the dashi, soy sauce and mirin. Stir, adjust the heat so it bubbles gently, and cover. Cook until the rice is almost fully tender, about 15 minutes.
When you remove the cover, the mixture should still be a little soupy (add a little dashi or water if it's dried out). Stir in the shrimp and peas, then raise the heat a bit and cook, stirring occasionally, until the rice is tender, the shrimp cooked and the mixture is still moist but not soupy, about 2 minutes. Taste and adjust the seasoning if desired and serve.
Yield:Makes 8 cups.
Combine the kelp and 8 cups water in a large pot over medium heat. Do not allow the mixture to come to a boil; as soon as it is about to, turn off the heat, add the bonito flakes and stir. Remove the kelp and reserve it to add to the rice if desired. Let sit for a couple of minutes, then strain. Use the dashi immediately or refrigerate for up to 2 days.