½ small yellow onion, peeled and finely chopped ½ cup mayonnaise 3 tbsp. freshly grated parmigiano-reggiano 2 tbsp. fresh parsley, finely chopped Sea salt and freshly ground pepper 8 slices of white bread
1. Preheat oven to 350°. Mix onion, mayonnaise, parmigiano-reggiano, and parsley in a medium bowl. Season with salt and pepper.
2. Remove crusts from the bread. Using a 1" round cookie cutter, cut bread into 32 rounds. Place on a cookie sheet and bake, without turning, until golden, 10–15 minutes.
3. Preheat broiler. Spread about 1 tsp. onion mixture onto each round, then sprinkle with more parmigiano-reggiano and brown under broiler for 1–2 minutes. Serve immediately.