saute onion in butter until soft. blend in the flour and cook stirring until you have a thick paste. gradually add the cream and cook, stirring until you have a smooth, thickened sauce. add salt, pepper and curry powder. blend well. mask the bottom of a buttered baking dish with the sauce, place a layer of noodles over the top, then a sprinkling of shrimp. continue layering until the shrimp and lasagne are all used. Save enough sauce to cover the top well. sprinkle with the cheese and a light dusting of paprika. bake in a preheated 375 degree oven for 20 minutes or until the top is bubbling.