Cut the chicken breast into bite-sized pieces.
Slice the onion and bell pepper thinly.
Heat olive oil in a pan and stir-fry the chicken breast.
When the chicken is half-cooked, add the vegetables and stir-fry.
Season with gochujang, chili powder, soy sauce, and minced garlic, then stir-fry.
Once all the ingredients are cooked, turn off the heat and sprinkle sesame seeds.