Gratineed Mustard Creamed Onions

Directions

1. 1.

   Cook onions in a large heavy pot of boiling salted water (2 teaspoons salt for 4 quarts water) until just tender, 25 to 30 minutes. Reserve 1 cup cooking water, then drain (reserve pot). Cool onions to warm, then peel.

2. 2.

   Melt butter in dry pot over medium heat. Add flour and cook, stirring, 2 minutes. Whisk in reserved cooking water, milk, and Sherry and cook, whisking frequently, until mixture is thickened, about 8 minutes. Whisk in mustards, nutmeg, and 1/2 teaspoon each of salt and pepper. Add onions to sauce and simmer 5 minutes.

3. 3.

   Preheat broiler.

4. 4.

   Transfer creamed onions to baking dish and sprinkle evenly with cheese. Broil 4 to 5 inches from heat until top is golden brown and bubbling, about 3 minutes.