1. Prepare grill.
2. Combine turkey, chopped watercress, 1/4 cup yogurt, 1 teaspoon cracked pepper, salt, and Worcestershire sauce in a bowl. Divide mixture into 4 equal portions, shaping each portion into a 1/2-inch-thick patty. Press remaining 1 teaspoon pepper onto both sides of patties.
3. Place patties on grill rack coated with cooking spray; cover and grill 5 minutes on each side or until done.
4. Spread 2 tablespoons yogurt over top half of each bun. Line bottom half of each bun with 1/4 cup trimmed watercress; top each with a patty, a tomato slice, and top half of bun.
carbo rating: 24