Dice the tofu into cubes.
Cut the chicken breast into small pieces.
Finely chop the onion, green onion, and garlic.
Heat olive oil in a pan and sauté garlic, onion, and green onion.
Add the chicken breast and cook until done.
Make the sauce by adding gochujang, soy sauce, pepper, and water.
Add the tofu and simmer together with the sauce.
Top the finished Mapo Tofu with green onion to finish.