Slice tofu into thin slices, about 1/2 inch (1.25cm) thick. Arrange them overlapping slightly on a plate that you will use to steam.
Drizzle sesame oil and sprinkle a pinch of salt and pepper over the tofu. Top it with julienned ginger. Cover the plate and steam until hot, about 6-7 minutes.
While steaming the tofu, make the sauce. Add a little olive oil to a small saucepan (or small deep pan) over medium heat. Add minced ginger and sauté until fragrant.
Add minced garlic and continue to sauté for a few seconds until fragrant. Then add fermented black beans and also sauté for a few seconds until fragrant.
Add oyster sauce and soy sauce to the saucepan. Give everything a quick stir and then add 1/2 cup (120ml) of water. Bring it to a simmer.
Combine cornstarch with 1/2 tablespoon of water to make a cornstarch slurry and gradually pour it into the saucepan while stirring to thicken the black bean sauce to your liking.
Once the tofu is hot, remove the plate from the steamer. Discard the liquid in the plate, then pour the black bean sauce over the tofu slices.
Scatter scallion slices and sprinkle Sichuan pepper over the tofu and serve right away with rice.