Cut the chicken breast into bite-sized pieces.
Slice vegetables like onion, bell pepper, and broccoli into easy-to-eat pieces.
Mix the sauce ingredients (ketchup, soy sauce, oligosaccharide syrup, black pepper) together beforehand.
Heat olive oil in a pan and stir-fry the chicken breast.
Once the chicken is cooked, add the prepared vegetables and stir-fry together.
When the vegetables are slightly cooked, add the pre-made sauce and stir-fry well with all the ingredients.
Once the sauce is evenly distributed among all ingredients, turn off the heat and transfer to a plate.