1/2 c. mayonnaise
1/4 c. grated Parmesan cheese
Salt and pepper to taste
Very, very thin onion slices
Dash Worcestershire sauce
1 1/2 inch bread circles (cut with shot glass) or rye rounds

Mix mayonnaise, cheese and seasonings. Place one onion slice on each bread circle. Cover onion with cheese mixture. Sprinkle with additional cheese. Broil until brown. (Can be made ahead, covered and refrigerated.) Double recipe for 50 circles.