French Onion Soup

2 cans chicken broth
2 cans water
2 medium onions, chopped
2 cloves garlic
2 soup spoons butter
2 soup spoons flour
salt and pepper
French bread toasted into garlic toast
400 grams gruyere cheese (or Swiss)
*Sauté onion and garlic in butter. Add flour, make paste. Slowly add broth. Simmer. Put in soup bowl, top with bread and grated cheese.