1 lb. Spanish onion, chopped fine
1/4 c. mayonnaise
1 egg yolk
1 tsp. salt
1 tsp. curry powder
1/2 tsp. sugar
1 loaf (8 oz.) party rye bread
1 lg. can grated Parmesan cheese
Butter

Put chopped onions in mixing bowl. Blend mayonnaise with egg yolk, salt, curry and sugar. Mix into onions. Spread buttered rye bread with onion mixture using about a tablespoon for each. Sprinkle generously with Parmesan and bake at 350 degrees for 15-20 minutes.