Grease 9x13 pan. If making to bake immediately, preheat oven to 350 degrees fahrenheit.
Dice bacon and cook, remove from skillet, and set aside. Keep grease in skillet.
Add hashbrowns to bottom of greased pan, top with one cup of cheese. *optional, defrost hashbrowns in microwave to speed up cooking. If preparing ahead of time, you can skip this step, and add 10-15 minutes to your baking time.
Add diced onion, peppers, and mushrooms to skillet to soften. Cook about 5-7 minutes.
In a bowl, add diced bacon, diced veggies, eggs, milk, one cup cheese and seasonings. Mix together, and pour over hashbrowns.
Bake at 350 for 45-55 minutes, until eggs are cooked through and hashbrowns are cooked to desired consistency.
This bake will keep in the fridge for up to a week.