For sauce:
In medium saucepan, melt butter and stir in flour.
Add milk at once.
Cook and stir until thick and bubbly.
Stir in cheese until melted.
For filling:
Stir together ½ cup sauce with crab, broccoli, and dillweed. Stuff pasta and use remaining sauce to pour on top.
Bake in baking dish and cover with foil for 25-30 min at 350 F.
Makes 4 servings.