Mapo Tofu

Ingredients

• Marinade for Ground Pork
• 1 1/2 tablespoons tapioca starch (can substitute cornstarch)
• 2 tablespoons soy sauce
• Other
• 1/4 lb ground pork
• 1 lb regular tofu (medium firmness)
• 1 leeks or 3 green onions
• 1/4 teaspoon salt
• 1 teaspoon chinese preserved black bean (fermented black beans, also called Chinese black beans)
• 1 tablespoon chili bean paste
• 3 tablespoons chicken stock or 3 tablespoons chicken broth
• 1 tablespoon cornstarch
• 2 tablespoons water
• 2 tablespoons light soy sauce
• freshly ground szechwan pepper
• 2 tablespoons oil, for stir-frying, as needed