Parmesan Cheese Rounds

Directions

1. 1
   Preheat the broiler to 425 degrees F.
2. 2
   With a 2 1/8-inch cookie cutter, cut 2 rounds out of each slice of bread.
3. 3
   Arrange the rounds on a baking sheet and place 5 inches from the heat source.
4. 4
   Toast the bread on one side until they are golden brown, 3 to 5 minutes.
5. 5
   Using a whisk, mix together the mayonnaise and Parmesan in a small bowl.
6. 6
   Remove the bread from the oven and turn the rounds over to the untoasted sides.
7. 7
   Spread each with a thin layer of mustard.
8. 8
   Put 1 onion slice on top and cover with about 1 teaspoon of the mayonnaise mixture, spreading the mixture across the onion and bread.
9. 9
   Broil until golden, about 1 minute.
10. 10
    Never take your eyes off these; the time varies with different ovens.
11. 11
    Work in batches of 24 rounds.
12. 12
    Serve one batch hot while the next is cooking.