Chicken Sandwiches With Onions And Mushrooms

Ingredients: 

Butter-flavored cooking spray as needed
1 small onion (4 oz) sliced thin
4 ounces mushrooms sliced thin
1 garlic clove minced
1 tablespoon low-fat low-salt mayonnaise
1/4 teaspoon prepared horseradish
2 teaspoons ketchup
1 teaspoon Worcestershire sauce
1/4 teaspoon Dijon mustard
4 boneless skinless chicken breasts abt 4 oz ea
4 multigrain crisp rolls - (abt 1 oz ea) halved horizontally

Yield: 

4 Servings

Method: 

Preheat grill or broiler.

Coat a nonstick skillet with cooking spray. Saut