In a bowl, mix all the ingredients for the filling until they become a well-combined, sticky mass (remember to save the water in which the mushrooms are soaked for later use).
Stuff the tofu
Take the tofu out of the container. Pat dry the surface with kitchen paper. Then slice it into square or rectangle blocks. Make sure they are thick enough to hold some filling (For your reference, my blocks are about 2½ cm/1 inch thick).
Use the tip of a knife to cut out a square/rectangle halfway through the tofu. Then scoop out the middle piece with a spoon making room for the filling.
Stuff each block of hollowed out tofu with the filling. It’s ok if it sticks out a little.
Fry the tofu
Pour oil into a frying pan/skillet over medium heat. Place in the tofu blocks with the stuffed side facing down. Fry until the top of the filling browns nicely.
With the help of a spatula or chopsticks, flip and turn the tofu blocks to lightly brown all other sides (It takes 10-15 minutes in total). Then transfer them to a serving plate.
Make the sauce
Discard the remaining oil in the pan leaving just a thin coating. Over low heat, fry garlic until fragrant.
While waiting for the garlic, mix light soy sauce, oyster sauce, cornstarch, white pepper and sugar with 5 tablespoons of the mushroom water saved from step 1.
Stir the mixture very well then pour into the pan. Turn off the heat and use the remaining heat of the pan to thicken the sauce (stir constantly with a spoon/spatula to avoid lumps).
When it reaches the desired consistency (just thick enough to coat the spoon), pour over the stuffed tofu. Garnish with scallions and serve with steamed rice.
Notes
1. You may omit the shrimp and use only pork for this recipe. In this case, add some finely chopped dried shrimp (rehydrated) if available.2. Firm block tofu works best for this recipe. You may also use medium-firm tofu but extra gentle handling is required as it’s more delicate. Please note that silken tofu/绢豆腐, no matter how firm, isn’t suitable for this dish.3. To make this dish gluten-free, use gluten-free soy sauce (or tamari) and gluten-free oyster sauce.