Prawn Curry from India

2 large onions
1/3 c butter
1 T curry powder
1 pound shrimp
1/2 t salt
1/4 c water
2 tomatoes
1 cucumber

Slice onions and cook in butter until golden. Add curry powder, shrimp, salt and water. Peel and seed tomatoes and cucumber, add cut in dice. Add and simmer all together for 15 minutes. Serves four.