Stir the potatoes, 1 1/3 cups of the onions, peas, cheese and bacon in a 13 x 9-inch (3-quart) shallow baking dish. Stir the soup and milk in a medium bowl. Pour the soup mixture over the potato mixture. Cover.
Bake at 350°F. for 30 minutes or until hot. Stir.
Sprinkle with the remaining onions. Bake for 5 minutes more or until the onions are golden brown.
Time-Saving Tip: To thaw the hash browns, cut off 1 corner on bag and microwave on HIGH for 5 minutes.