Cheesy Light Puff Bread

1½ cups low-fat mayonnaise 8 ounces reduced-fat cheddar, finely shredded 2 tablespoons dry ranch dressing mix 1 loaf (1 pound) French bread, split horizontally Heat broiler. In a medium bowl stir mayonnaise, cheese and dressing mix until well combined; spread on cut sides of bread. Place bread cut-side up on a cookie sheet and broil until bubbly. Serve immediately. Serves 12.