French Onion Soup - Challenge Dairy

Ingredients

• ¼ cup Challenge Unsalted Butter (½ stick)
• 6 medium yellow onions, thinly sliced (6 cups)
• 1 Tablespoon all-purpose flour
• ¼ teaspoon black pepper
• 3 cans “lower sodium” beef broth (14-ounces each)
• 1½ cups water
• ¼ cup dry sherry
• 1 cup grated Swiss cheese
• ¼ cup grated Gruyere cheese
• 6 slices sourdough French bread, toasted and cubed