Preheat oven to 425. Line a baking sheet with aluminum for easy clean up. Lay green beans out on the baking sheet and drizzle oil over them. Season with salt, pepper, and garlic powder. Toss to evenly coat.
Spread beans on the sheet so that they all lay flat and place on the lower third section of your oven. Bake 10 minutes, shake the pan to turn; bake 5 minutes longer. Remove from oven and sprinkle with grated cheese.