In your largest bowl mix first 8 ingredients
15 Eggs, lightly beaten
3 Cups milk
2 Tbsp mustard
1 tsp salt
½ tsp black pepper
5 C. Italian style Garlic Croutons
2 C. shredded sharp Cheddar cheese
1 Can cream of mushroom soup
1 Cup frozen hash brown potatoes
Now Add-8oz. cooked & crumbled Italian Sausage that you buy already cooked & crumbled from Gordon Foods [I freeze in 8 oz. pkgs then it's ready to put in] Let sit out for a couple hours for bread crumbs to absorb the eggs.
Spray 10 Oval corning ware 16 oz casserole dishes [or a 9" x 13" pan] & divide equally into them.
Now add any veggies [onions, green/red peppers & mushrooms] that you like but if you're putting mushrooms in- microwave them for one minute w/1tsp butter to keep the brown from running while they sit in the refrigerator. To make individually- First put guests initials on the corning ware dishes with a permanent marker [it'll come off w/Ajax when cleaning them later] then add the veggies they prefer off their reservation confirmation.
Refrigerate overnight or up to 4 days. Then bake uncovered @ 350 for 1 hour, let sit for 5 minutes before serving. Serve with fresh diced tomatoes mixed with mild salsa served on the side or canned diced garlic/basil/oregano tomatoes.