In a high baking pan, place 5 KANAKI Filo Pastry sheets and oil them. Press them with your fingers into the shape of the baking pan. With a small pair of scissors, cut the excess parts of the sheets. Then, bake in a preheated oven on the bottom rack at 175οC, with extra heat on the oven elements, while you prepare the ingredients for the omelette. Cut the mushrooms, bacon and onion in thin slices. Break the eggs in a large bowl. Add a cup of milk. With a fork, stir well for the egg yolks to break. Add the bacon and mushrooms. Add the cheese in bits, salt and stir. Take the baking pan out of the oven and add the ingredients. Grate a little cheese for extra taste. Finally, add the onion. Bake at 170°C with extra heat on the oven elements, for 45 min.