In a large bowl, gently whisk together the eggs, evaporated milk, kosher salt, pepper, onion powder, and garlic powder until well combined. Set aside.In a greased 8x8 baking dish, evenly spread the hash brown potatoes. Evenly sprinkle bell peppers on top. Layer with half of the bacon pieces, followed by half of the green onions. Spread shredded cheddar evenly on top, followed by remaining bacon and remaining green onions. Pour egg mixture over entire dish.Cover tightly and chill overnight (you can also bake right away if you're preparing the entire dish in the morning.)Preheat oven to 350F, with rack on lower middle position. Let casserole sit at room temp while oven is preheating. Bake uncovered, 40-50 minute or until top is golden brown and puffy/set. Let rest at room temp 5-10 minutes before serving. Leftovers can be chilled and reheated nicely.