Components: 1/3 cup balsamic vinegar,2 teaspoons newly ground black pepper,2 teaspoons kosher salt,3 tablespoons olive oil,2 oranges — peeled, cut into rounds, and seeded,1 medium red onion, cut into 1/2- inch pieces,1 1/2 pounds sirloin steak, about 1 1/2 inches thick, cut into 2-inch cubes,1 lot watercress, cleaned
Directions: