Cut flounder fillet into chunks, blend with soy sauce and half of wine. Add salt, half of the corn flour, an egg white, mix the products and let stay for 10 minutes. Take the fish off the marinade and fry in a portion of vegetable oil until light-brown. Dry.

Heat the rest vegetable oil, put grated ginger and chopped onion and fry for 1 minute. Add cut mushrooms and fry for 1 minute more.

Mix the rest vegetable oil and flour, add 1 tablespoon of water, combine with mushrooms and heat, stirring, for 2 minutes.

Put the ready flounder on a serving platter before serving and cover with the prepared mushroom sauce. Garnish with lemon slices and greens.