Heat oven to 350 degrees F.
In large bowl, whisk together the soup, 3/4 cup water and 1/8 teaspoon black pepper. Add broccoli, turkey, pearl onions and 1 cup onion rings; stir to combine. Pour into shallow 2-quart casserole.
Bake, uncovered, in 350 degree F oven for 30 minutes. Sprinkle remaining 1 cup onion rings over top. Bake another 5 minutes or until top is browned and bubbly. Makes 6 servings.