Cauliflower Mousse

Directions

1. 1
   Put oven rack in middle position and preheat oven to 350°F. Butter souffle dish, then line bottom with a round of parchment or wax paper and butter paper. Chill dish until ready to fill.
2. 2
   Cook cauliflower with 2 teaspoons salt in a 3- to 4-quart pot of boiling water, uncovered, until tender, 15 to 18 minutes. Drain cauliflower well in a colander, then pure in a food processor until smooth.
3. 3
   Melt butter in a 1-quart heavy saucepan over moderately low heat. Add flour and cook, whisking, 2 minutes. Add milk in a stream, whisking, then add white pepper, nutmeg, and remaining 1/2 teaspoon salt, whisking. Bring to a boil over moderate heat, whisking, then reduce heat and simmer, whisking constantly, 2 minutes. Remove from heat and cool bechamel, 5 minutes.
4. 4
   Whisk cauliflower pure into bechamel, then add beaten eggs, whisking until combined well. Transfer mixture to souffle dish and put dish in a 13- by 9-inch roasting pan, then add enough boiling-hot water to pan to reach halfway up side of souffle dish. Bake until center of mousse is firm to the touch and mousse begins to pull away from side of dish, 35 to 40 minutes.
5. 5
   Remove mousse from oven and water bath. Position oven rack so that top of mousse will be 4 to 6 inches from broiler, then preheat broiler.
6. 6
   Run a knife around edge of souffle dish, then place an ovenproof platter on top of souffle dish and invert mousse onto platter. Sprinkle cheese evenly over top of mousse and broil until cheese is melted and golden brown, about 2 minutes.