Onion soup

Instructions
In a saucepan make butter melt, add the sliced onions and, when they are dried, mix half a tablespoon of flour.



Add 2 scarce liters of boiling salted water, sprinkle abundant white pepper and cook for 45 minutes.



Cut bread into half a centimeter thick slices, toast them in the oven, then arrange them in a bowl alternating layers of the two types of cheese mixed.



When the soup is ready pour it into the bowl, put the lid and bake in the hot oven for 10 minutes.



Serve the soup accompanying it with grated Grana cheese to taste.