Frisée and Endive Salad with Warm Brussels Sprouts and Toasted Pecans

Ingredients:
3 tablespoons white-wine vinegar
2 tablespoons water
1 tablespoon Dijon mustard
1/4 cup minced shallot
1/2 teaspoon salt
1/4 teaspoon black pepper
6 tablespoons olive oil

For salad
1/2 stick (1/4 cup) unsalted butter, cut into pieces
1 lb Brussels sprouts (preferably small), trimmed and halved lengthwise (quartered if large)
1/2 cup pecan halves, halved lengthwise
1 teaspoon salt
6 oz frisée, trimmed and torn into bite-size pieces (4 cups)
3 Belgian endives (1 lb), cut crosswise into 1/2-inch slices

Directions:
Make vinaigrette:
Whisk together vinegar, water, mustard, shallot, salt, and pepper in a small bowl, then add oil in a slow stream, whisking.

Preheat oven to 400°F.
Melt butter in a large shallow baking pan (1 inch deep) in lower third of oven, about 3 minutes. Toss sprouts in pan with butter, pecans, and salt.
Arrange sprouts, cut sides down, in 1 layer and roast in lower third of oven until undersides of sprouts are golden and nuts are fragrant, 12 to 15 minutes.
Whisk vinaigrette, then transfer warm sprouts and nuts to a large bowl and toss with frisée, endive, and enough vinaigrette to coat.
Serve immediately.