Preheat the oven to 400*F. Spray a 9 by 13-inch baking dish with non-stick cooking spray. Set aside.
Add the potatoes to a large bowl. Toss together with the oil, seasonings, pepper, and red pepper flakes, mixing well together.
Add the sausage to a skillet along with the water. Cook and stir over medium high heat until the water has evaporated and the sausage has browned. Add the sausage to the bowl of potatoes.
Add the butter to the skillet. Add the onions and garlic. Cook until the onions are translucent and soft without browning. Pour this into the bowl with everything else. Add the drained green beans and mix everything together well. Pour into the prepared baking dish.
Cover tightly with foil and bake in the preheated oven for 40 minutes, or until the potatoes are fork tender.
Uncover and enjoy! Serve hot.