Cut the tofu into 1-inch cubes and set it aside.
Heat the vegetable oil in a pan, add the Sichuan peppercorns, and fry them until fragrant. Remove the peppercorns and discard them, keeping the oil in the pan.
In the same pan, add the ground beef and cook it until it’s browned.
Add the Sichuan bean paste and fermented black beans to the pan, stir them well with the beef.
Add the garlic and half of the chopped green onion to the pan and stir-fry them until fragrant.
Add the beef broth, soy sauce, and tofu to the pan, bring the broth to a boil, and let it simmer for about 10 minutes.
Mix the corn-starch with a little water to make a slurry, then add it to the pan and stir well until the sauce thickens.
Serve the Mapo Tofu hot, garnished with the remaining green onion.
