Roasted Pear, Prosciutto, and Watercress Salad with Candied Pecans

Ingredients

• 2 tablespoons unsalted butter
• 1½ cups pecan halves, may substitute walnuts
• generous pinch salt
• 1/4 cup brown sugar
• 1 tablespoon unsalted butter
• 2 (about 1 pound total) ripe but firm Bosc or Anjou pears, cored, each cut into 6 long wedges
• Salt
• freshly ground black pepper
• 3 sprigs thyme
• 3 tablespoons sherry vinegar
• 1 teaspoon honey
• 1 teaspoon Dijon or grainy mustard
• 2 tablespoons extra virgin olive oil
• 2 tablespoons chopped chives, optional
• 6 cups trimmed bite-size watercress sprigs (a 4-ounce bag), washed and dried well
• 4 thin slices
• Prosciutto