Rinse the sushi rice under cold water in a fine mesh strainer until the water runs clear, about 2-3 minutes. Drain well.

Combine the rinsed sushi rice with water in a medium saucepan. Bring to a boil over high heat, reduce to low, cover, and simmer for 18-20 minutes.

Remove from heat and let it sit covered for an additional 10 minutes to steam.

Fluff the rice with a fork to achieve a light texture and set aside to cool slightly.

Heat a skillet over medium heat and add vegetable oil. Once hot, add shiitake mushrooms and sauté for 5-7 minutes until golden brown.

Incorporate minced garlic, grated ginger, white miso paste, soy sauce, and sesame oil to the sautéed mushrooms. Cook for an additional 2-3 minutes.

Pour the mushroom mixture over the fluffed rice and gently fold together, ensuring the rice remains fluffy.

Transfer the mixture back into the skillet, pressing down gently to form an even layer. Cook for 10-15 minutes until the bottom is crispy and golden.

Garnish with chopped green onions and optional sesame seeds. Serve hot.