Mushroom Swiss Patty Melt

Mushroom Swiss Patty Melt
ingredients:
Pam Cooking Spray,
Bowl & Basket 100% Ground Beef Burger (1/3 pound),
Onion,
Mushrooms,
Pepperidge Farm Jewish Rye Soft Bread,
Bowl & Basket Butter,
Salt,
Great Value Sliced Swiss Cheese,
Hellmannʼs Mayonnaise