Bring 3 cups of water to a boil and add 2 teaspoons of salt. Add 1 cup of rice. When the water comes back to a boil, reduce the heat and simmer for 15 mins stirring every 3 mins. Taste if ready. Drain and set aside.
In a frying pan heat oil and cook mushrooms for 10-15 mins until deep golden brown and set aside.
In a small sauce pan over medium heat combine soy sauce and water, once hot add in corn starch, stirring constantly. Take the mixture away from the heat and let cool slightly. Add sesame seeds, brown sesame oil, lemon juice, sake and pepper, stir everything to combine. Pour the mixture over the seaweed and leave to marinade for two hours.
Once ready in a frying pan heat oil and add rice, mushrooms and seaweed, mix to combine and serve warm sprinkled with more sesame seeds and soy sauce if desired. Enjoy!