Chop the chicken breasts, potatoes, carrots, onions and pepper into small cubes, separately.
Braise the onions and pepper in a pan with a little oil until softened, add the carrots and potatoes, stir. Add the chicken meat, stir and braise until it changes color. Add the peas, salt and fry on low heat, throw in the parsley and finely chopped garlic, remove the dish from the heat.
For the bechamel, dissolve the flour in the cold milk, add the egg yolk, black pepper and salt to taste. Stir and put it on a low stove to cook until thickened.
Distribute the vegetable mixture evenly in an oiled tray but set aside 3-4 tbsp of it. Pour the bechamel over the dish, sprinkle with the grated cheese evenly and lay out the set aside vegetable mixture in the middle of the tray in a circle.
Bake the dish in a preheated 356°F (180 °C) oven until the cheese gains a golden crisp.
A practical and very tasty dish with Bechamel sauce in the oven.