Ingredients:

6 medium-size onions, peeled
6 cups boiling water
2 tsp. salt
3 tbsp. butter, melted
2 tbsp. flour
½ tsp. black pepper
1 cup milk
1½ cups fresh or frozen peas, lightly steamed

Procedure: 

1. Cook onions uncovered in boiling water to which 1-1/2 teaspoons of salt has been added for 30 minutes, or until almost tender.  Drain and cut in half from top to bottom.  Take out the innermost layers, leaving 2 or 3 outside layers to form a cup. 
2. Preheat oven to 400°F.  Place onion cups in baking dish with 2 tbsp. melted butter.  Bake in oven for 30 minutes or until lightly browned, basting frequently with melted butter.
3. Meanwhile, melt remaining tablespoon butter in saucepan. Blend in flour, remaining 1/2 teaspoon salt and pepper. Slowly stir in milk.  Bring to a boil for 2 minutes, stirring constantly. Add peas until heated thoroughly.  To serve, fill onion cups with creamed peas.

Recipe courtesy of National Onion Association.