1. Combine chicken, 1/4 cup Hellmann's® or Best Foods® Real Mayonnaise and onion in large bowl.
2. Spread chicken mixture on 4 bread slices, then top with cheese. Evenly spread remaining 4 bread slices with mustard, then place on sandwiches, mustard-side-down. Coat outside of sandwiches with remaining Mayonnaise.
3. Cook sandwiches in 12-inch nonstick skillet or grill pan over medium heat, turning once, 6 minutes or until sandwiches are golden brown and cheese is melted.
Cost per recipe*: $8.60
Cost per serving*: $2.15
*Based on average retail prices at national supermarkets.