2-ounces canned mushroom pieces and stems, drained
1/2 of a 2.8-ounce can french-fried onion rings
1 loaf (8-ounce) party rye or pumpernickel bread
In a bowl, stir together the mayonnaise, Parmesan, mushrooms, and onion rings. Spread on lightly toasted party rye or pumpernickel. Place the canapes on a baking sheet and broil until the topping is bubbly.