01 -  Preheat oven to 375°F (190°C). Grease a 9x13-inch baking dish. 
 02 -  Spread thawed hash browns evenly in the dish and drizzle with olive oil or butter. Bake for 15 minutes to crisp slightly. 
 03 -  Whisk eggs, milk, salt, pepper, garlic powder, and onion powder in a large bowl. 
 04 -  Remove the dish from the oven and layer cheese, meat (if using), bell peppers, and onion over the hash browns. 
 05 -  Pour the egg mixture evenly over the top. 
 06 -  Bake uncovered for 35–40 minutes, or until the center is set and the top is golden. 
 07 -  Let cool for 5–10 minutes before slicing. Garnish with parsley if desired.