Mix 1
1 med. onion - finely chopped 
1 rib celery - finely chopped
4 leaves green onion tops - finely chopped
1 stick butter

Mix 2
1/3 cup all purpose flour
2 sm. (5oz.) cans evaporated milk
1 Tsp. of dried parsley flakes or small handful of fresh chopped
1 Tsp. Worcestershire
1/4 Tsp. "Old Bay" or Tony's seasoning
pinch of garlic powder
Salt & Pepper to taste
2 egg yolks beaten well

Last:
1 pound lump crabmeat (see note below)
Gratin Dishes or shallow casserole
8 to 12 oz. shredded cheddar cheese...