**Preheat oven to 350° or 375° (see note)
Cook 1 lb of bacon (I cook bacon in the oven on foil covered sheet pans in a 350° for about 30 minutes or until it is the desired crispiness)
Fry breakfast sausage until cooked through and place in strainer to drain off any grease.
Shred both types of cheese.
Crack 8 eggs into a medium bowl and whisk to break up eggs. Add milk, season salt, mustard powder, and granulated garlic and whisk thoroughly.
Spray 9 x 13 inch casserole dish with cooking spray and line bottom of the pan with frozen tater tots.
Spread sausage on top of the tots, then the bacon on top of the sausage.
Combine both kinds of cheese and sprinkle over the sausage and bacon.
Pour the egg mixture evenly over the entire dish and cover with foil.
At this point you can refrigerate the casserole overnight and bake off in the morning, or you can cook right away.
** If you are cooking right away, bake in a 375° oven, covered, for 30 minutes. Then remove the foil and turn the oven down to 350° and cook for another 25-35 minutes. If you made the casserole ahead of time and are cooking the next morning, bake in a 350° oven for 30 minutes with the foil on and 25-35 minutes with the foil off. Or until the eggs are set in the center of the casserole. (To test, insert a knife in the center of the dish and make sure the eggs are set and no longer runny.)
Allow to rest on the counter for about 5-10 minutes before slicing and serving.
Garnish with thinly slice scallions or chopped parsley if desired.