Cut the tofu into cubes.
Finely chop vegetables such as onion, carrot, and bell pepper.
Heat cooking oil in a pan and sauté minced garlic.
Add the onion, carrot, and bell pepper, and stir-fry.
Add gochujang (Korean chili paste), soy sauce, doubanjiang (spicy bean paste), and sugar, and stir-fry.
Add the tofu and mix until the sauce is evenly coated.
Add water and starch water to thicken the sauce.
Finish with sesame oil and pepper.