Advance preparation. Defrost broccoli and let drain. Saute or boil onions until tender.
In saucepan melt 2 TBS of the butter, blend in flour, [1/4 tsp salt], [dash pepper]. Add milk, cook and stir until thick and bubbly.
Reduce heat blend in cream cheese till smooth. Place vegetables in 1 1/2 qt casserole. Pour sauce over mix lightly. Top with cheddar; cover and chill. Melt remaining butter:, toss wfh bread crumbs. Cover, chill.
Before serving, bake casserole covered at 350"F for 30 minutes. Sprinkle crumbs all over, bake uncovered till heated through, about 30 minutes more. Serves 6
Thanksgiving - 2x-4x Batch