Mapo Tofu

In a small bowl, stir together all meat ingredients until combined evenly. Set aside while preparing remaining ingredients.

In a deep-sided large skillet over medium-high heat, heat oil. Add marinated meat and cook, stirring frequently, until deeply golden and almost crispy, about 5 minutes. Transfer meat to a clean bowl and keep fat in the skillet.

Return skillet to medium-high heat, and add chili paste, black beans, and Szechuan peppercorns, and stir until fragrant, about 30 seconds. Add in garlic, ginger, and scallions, and stir until soft and fragrant, 1 to 2 minutes.

Reduce heat to medium. Add sugar, tofu, and water, and bring to a boil. Periodically, gently shake the pan to coat tofu in the sauce. Cook until liquid reduces by half, 12 to 15 minutes.

In a small bowl, stir cornstarch with soy sauce, sesame oil, vinegar, and MSG, if using, until smooth. Drizzle cornstarch slurry into the skillet, and gently stir to distribute evenly, allowing the tofu to break into smaller pieces naturally. Cook until sauce thickens and becomes shiny, 1 to 2 minutes. Sprinkle cooked meat evenly across the tofu.

Drizzle with chili oil and sprinkle with more scallions, if desired, before serving with rice.