Preheat an oven to 350 F. Coat a 9x13 baking pan with nonstick spray; set aside.
In a large skillet, add the olive oil over medium high heat. Once the oil is hot and begins to shimmer, add the chopped onions and bell peppers. Sauté until tender, about 7 to 8 minutes, then remove from the heat.
2 Tablespoons olive oil, 1 onion, finely chopped, 1 green bell pepper, finely chopped
In a large mixing bowl, stir together the onions and peppers, hash browns and cheddar cheese, breaking up the hash browns into smaller pieces. Spread the mixture evenly into the greased baking dish.
1 (32 ounce) bag frozen, shredded, hash brown potatoes, thawed, 2 cups shredded cheddar cheese
In the same mixing bowl, whisk together the eggs, milk, garlic powder, salt and pepper. Pour over the top of the potato mixture. Sprinkle the Swiss cheese over the top.
6 eggs, ½ cup whole milk, 1 teaspoon garlic powder, 2 teaspoon kosher salt, ½ teaspoon ground black pepper, ½ cup shredded Swiss cheese
Bake for 30 to 40 minutes until the center is cooked through and springs back when touched. Sprinkle with the parsley and serve.
2 Tablespoons fresh parsley, minced