Anne's Awesome Breakfast Casserole Recipe - YUMMY!!!

I know I promised I would post this for you guys (with Anne's permission of course!) - sorry it took a little while.

This is the casserole I made in Whistler (though the sausage there was lousy so it's much better usually), Sonoma, for the Landing Party at our house for the last shuttle flight and Winter Park. It is ALWAYS a crown pleaser :)

DAY BEFORE

1 lb. bulk sausage (Bob Evans original, or any good, plain breakfast
sausage)
1/4 cup finely chopped onion

   Brown sausage / add chopped onion toward end (in time for it to become
soft and translucent)
   Drain fat
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Basic white bread (20 +/- slices) -- crust removed
1/4 Cup softened butter (best to use real butter)
8-10 slices of pre-sliced cheese (cheddar or American may be used...whatever you prefer)

   Butter one side of bread and line bottom of 9 x 14 (or slightly smaller)
Pyrex casserole pan, butter down
   Cover bread with a (solid) layer of cheese slices
   Cover cheese with an even layer of the browned/drained sausage & onion
   Top with a layer of un-buttered bread slices
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10-12 beaten eggs (depending on size of eggs and how eggy you want it)
3/4 Cup milk
1/2 teas. dry mustard
1/8 teas. pepper

   Mix well and pour slowly and evenly over casserole
   Cover and refrigerate overnight
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MORNING 

Remove casserole from refrigerator (set it out for 1/2 to 1 hour to warm up
if possible - if not, sometimes I put it in the microwave for a minute or so
in order to take the chill off the center -- just to make it cook a little
more evenly) 

Preheat oven to 350*

3/4 Cup Cornflakes (enough to generously cover the casserole)
1/4 Cup melted butter

   Cover casserole with Cornflakes
   Drizzle melted butter over Cornflakes
   Bake one hour at 350*