Mapo Tofu

Ingredients

• 1 pound soft (not silken) tofu, cut into 1/2-inch cubes
• 8 ounces ground pork (or ground beef)
• 2 tablespoons oyster sauce
• 1 tablespoon dark soy sauce
• 4 tablespoons cornstarch, divided
• 3 tablespoons vegetable oil, divided
• 3 cloves garlic grated on a microplane grater
• 1 tablespoon fresh ginger grated on a microplane grater
• 3 scallions, white and green parts finely chopped separately
• 3 tablespoons Pixian broad bean paste (douban jiang)
• 1 tablespoon chili garlic sauce (or 1 tsp. hot pepper flakes)
• 1 tablespoon Chinese fermented black soybeans, chopped (dou chi), or black bean garlic sauce
• 1 teaspoon toasted sesame oil
• 1 tablespoon brown sugar
• 1 teaspoon soy sauce
• 1.5 teaspoons ground Sichuan peppercorn, divided
• 1 cup low-sodium chicken stock
• 1 cup peas, thawed if frozen