- 2 lb white pearl onions, left unpeeled
- 1 1/4 teaspoons salt
- 3 tablespoons unsalted butter
- 1 tablespoon all-purpose flour
- 1 cup heavy cream or half-and-half
- 1/4 teaspoon black pepper
- 1/4 teaspoon freshly grated nutmeg
- 1 1/2 cups coarse fresh white bread crumbs (from 1/4 lb bread with crusts removed)
Blanch onions in a 3-quart pot of boiling water 1 minute, then drain in a colander and transfer to a bowl of cold water to stop cooking. Drain and peel onions.
Put onions and 1 teaspoon salt in same pot and add fresh water to cover by 1 inch. Bring to a boil, then reduce heat and simmer, covered, until onions are tender, about 20 minutes. Drain well in colander and transfer to a buttered 2-quart baking dish.
Put oven rack in middle position and preheat oven to 350°F.
Melt 1 tablespoon butter in a 1- to 2-quart heavy saucepan over moderately low heat, then add flour and cook, stirring, 1 minute. Add cream in a stream, whisking, and bring to a simmer, whisking. Simmer sauce, stirring occasionally, 2 minutes. Stir in pepper, nutmeg, and remaining 1/4 teaspoon salt and pour sauce over onions.
Melt remaining 2 tablespoons butter in a 10-inch nonstick skillet over moderately low heat, then add bread crumbs and cook, stirring, until golden, 3 to 5 minutes.
Sprinkle toasted crumbs evenly over onions and bake until sauce is bubbling, about 30 minutes.