Radicchio with Spring Peas

INGREDIENTS

• 1/2 head radicchio, very thinly sliced (about 2 cups)
• 1 1/2 cups shelled fresh peas (from about 1 1/2 pounds peas in pods) or thawed frozen peas
• 2 tablespoons water
• 1 tablespoon cider vinegar
• 1 tablespoon extra-virgin olive oil
• 1 teaspoon granulated sugar
• 1/2 teaspoon coarse salt
• 1/8 teaspoon freshly ground pepper