Sift flour, salt and cayenne pepper (and curry powder if using) into a mixing bowl. Rub in butter, mix in half a cup of grated cheese.
Add milk and mix to form a soft dough. Don't be too worried about how well mixed it is. Spread evenly over the base of a greased lamington tin or baking dish. The size of the dish depends on how thick you want the base.
Saute bacon and onion until transparent but not browned. Remove from heat and stir in sour cream. Spread evenly over dough and cover with remaining cheese.
Bake in hot oven 200 degrees for 25-30 minutes. Enjoy!