Prepare a whole box of silken. Put it on the plate and Steam it on boiling water for 8 minutes.
Mix well corn starch, and 2 tsp of water. Set aside.
Cook the sauce. Add vegetable oil in a hot saucepan, then add in the ginger, garlic and green onion, sauté for about one minute or until they barely turn golden brown.
Add in the mushroom sauté for another one minute, then add soy sauce, a pinch of white pepper, keep on stirring until the sauce all mixed up evenly, then add in water or vegetable stock. Keep on cooking. when it’s boiling or you can see it start to bubble up, add in the starch water to thicken up the sauce. Then turn the heat off and add in 1 tsp of toasted sesame oil to enhance the flavor.
When the tofu is ready, take it out from the steamer. Drain the water out, pour the sauce all over the tofu.