Dice the tofu and vegetables into small cubes.
Heat cooking oil in a pan and sauté minced garlic and ginger.
Add chopped onion, carrot, and bell pepper, then stir-fry.
Add the tofu and gently mix.
Season with black bean paste or chili paste, soy sauce, and chili powder.
Pour in vegetable stock and bring to a boil.
Add starch slurry to adjust the thickness.
Finish by adding chopped green onion.