Place 2 slices of tai on a microwave-safe plate, sprinkle with sake, cover loosely with plastic wrap, and microwave at 600W for 30 seconds.

In a bowl, crack the eggs and mix well. Add the remaining egg mixture ingredients and strain the mixture.

Trim the root ends of the shimeji mushrooms and separate them. Cut the kaiware sprouts into halves.

In two serving bowls, place the remaining tai slices (2 per bowl), shimeji mushrooms, and pour half of the egg mixture into each bowl.

Place the bowls in a steamer with boiling water. Cover with a lid wrapped in a cloth and steam on medium heat for 2 minutes.