Cut the chicken breast and all vegetables into bite-sized pieces.
Add cooking oil to a pan and preheat over medium heat.
Add the chicken breast and stir-fry until the surface is slightly cooked.
Add the vegetables (onion, bell pepper, broccoli, etc.) and stir-fry together.
Season with salt and black pepper.
Once the chicken breast and vegetables are cooked through, turn off the heat and plate the dish.