How to cook
Cut the meat into cubes (small pieces). Cut the onion into crescents.
Peel the mushrooms, remove the stalk (if desired, you can use it by cutting it in two), and cut them into small cubes - if it is a larger mushroom cut into 6, and if it is a smaller one - into 4 pieces.
Fry the onion in a little oil, add the mushrooms and after 10 minutes of frying add the chicken fillet. Add oil if necessary. Fry until golden or until the color you want.
Shortly before removing from the heat, add salt and pepper, mix very well.