Fry 1 sliced onion in 50g of butter until golden brown.
Lift out and keep hot. Fry 1 peeled, sliced apple in the same butter to brown on both sides and soften - remove and keep warm.
Fry two sausages per person (or one cumberland), and transfer to a warmed serving dish. Pour off the majority of the fat (leaving approximately 1 tbsp) add 2 tsp of flour and stir well. Add 150ml cider and bring to the boil, stirring. Boil hard for five minutes. Add back to the pan the onions and apples, reboil, then serve over the sausages.
Good with mashed potatoes.