Drain juice from clams and save liquid. Chop clams. Melt butter.
Blend in flour and seasonings. Mix clam juice with milk to make 1 1/2
cups. Add to flour blend slowly while cooking over low heat. Stir
constantly until mixture is thick and smooth.
Add clams. Place half of potatoes in greased casserole, sprinkle half
the onions over potatoes and cover with half the sauce. Repeat. Sprinkle
with cheese and paprika. Bake at 175C/350F for 45 minutes.