Cut the mushrooms into medium cubes.
Finely chop the onion.
Grate the cheese on a coarse or fine grater.
Cut the chicken fillet into small pieces 1-1.5 cm in size.
Heat a frying pan and pour in a tablespoon of vegetable oil. Squeeze a clove of garlic and fry it for 1 minute until golden and fragrant. Add finely chopped onion and fry it for 3-4 minutes. Add mushrooms to the onion and fry them for another 5 minutes. Add a little salt and pepper.
In another frying pan, lightly fry the chicken in vegetable oil for about 2-3 minutes. Lightly salt it. No need to cook it until done, it will finish in the oven.
Take a baking dish. Place the chicken on the bottom.
Place the onions and mushrooms as the next layer.
Pour cream over everything.
Sprinkle with grated cheese on top. Bake the julienne in the oven for 15 minutes at 200°C.
Julien is ready. Enjoy your meal.