Cut the chicken breast, mushrooms, and onion into bite-sized pieces.
Add olive oil to a pan and stir-fry the chicken breast.
Once the chicken is cooked, add the onion and mushrooms and stir-fry.
Add the rice and stir-fry until all the ingredients are evenly mixed.
Season with soy sauce, salt, and pepper.
Once everything is well-cooked and mixed, it's ready to serve.