Crab Au Gratin is a rich dish that goes well as a side with other seafood main courses such as stuffed flounder.

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, or, your favorite

Preparation

In a saucepan on med-low heat melt the butter. Add the remainder of mix 1 above. Cook until onions are clear and soft, don't brown. 

Stir in mix 2 in the order given (except egg) thoroughly mixing in each ingredient before the next is added. Add the milk a little at a time as you stir. Raise heat to med. and get the mixture bubbling then remove from heat. Take a spoon out to taste. Add the egg and mix well. Cover and let sit for 10 minutes. Add seasoning if needed (see note below). 

Note: Crab meat purchased at the grocery will not be seasoned. If you're using crab meat that you peeled from a batch of boiled crabs it will be seasoned. Keep this in mind when adding seasoning. Using boiled and peeled meat will flavor the dish so taste it before adding any seasoning.

Add crab meat to saucepan and mix well. Fill gratin dishs to 1/4" from top of dish, smooth top with a spoon and sprinkle cheese on top.

Bake at 375ºF until cheese is brown and crusty.