French Onion Soup
["4 to 5 large yellow onions (about 1 1/2 lb.)", "3 Tbsp. butter or margarine", "1/4 tsp. coarsely ground black pepper", "1 Tbsp. all purpose flour", "3 cans (10 3/4 oz.) beef broth, undiluted", "3 c. water", "1 bay leaf", "6 to 8 slices French bread", "2 Tbsp. Parmesan cheese", "1 c. grated Gruyere cheese or Swiss cheese"]
["Step 1.", "Peel onions; cut off and discard root ends.", "Using a large knife, slice onions thinly.", "In a 4 qt. saucepan, over medium high heat, melt butter.", "Add onions and ground black pepper to butter."]
["yellow onions", "butter", "ground black pepper", "flour", "beef broth", "water", "bay leaf", "bread", "Parmesan cheese", "Gruyere cheese"]