Cut tofu into 4 slices. Place tofu between 2 paper towels. Let stand until paper towels have absorbed much of the liquid, about 10 minutes. Drain and cut into 1/2-inch cubes.
Whisk chicken broth, chile-garlic sauce, soy sauce, cornstarch, and black bean sauce together in a bowl.
Heat a wok or nonstick skillet over medium heat. Add pork; cook and stir until browned and crumbly, 5 to 7 minutes. Add garlic and ginger; cook, stirring constantly, until softened, about 2 minutes. Stir in the broth mixture; bring to a boil. Reduce heat to low; simmer sauce until thickened, about 2 minutes.
Toss cubed tofu into the sauce; simmer until heated through, about 2 minutes. Remove from heat; stir in green onions. Spoon ma po tofu over hot rice. Season with black pepper.