Cut the onion into strips, carrots in a semicircle, pepper into cubes, and champignons in half, mix. Cut the tomatoes into circles. Cut the potatoes into half-centimeter circles and fry it on both sides until golden brown. Cut the mullet fillet into thin slices at an angle of 45 degrees.
Put half of the fried potatoes on the bottom of the baking dish, salt a little, then put the layers of fish and lightly salt again. Top with a mixture of vegetables and mushrooms and a mug of tomato. Finish with a layer of fried potatoes and drizzle with sauce.
Send to the oven preheated to 240 degrees. When the sauce begins to boil, add the grated cheese on a coarse grater. Cook until cheese is browned.