Preheat oven to 350 degrees F.

Place the potatoes in a large pot and cover with water. Boil until soft then drain. Heat the butter and milk together and pour into the pot with the potatoes. Mash with a potato masher and taste to see if you need to add salt and pepper.

For the sausage and onion gravy start by heating a large frying pan over medium to medium low heat with the olive oil. Add in the sausages and fry until golden in color then remove and set aside. Add in the onions and cook until softened and golden. Add in the flour, brown sugar and vinegar and cook until light brown color. Slowly whisk in the beef stock. Add the sausages back into the gravy and bake for 30 minutes.

To serve place 2 sausages on top of the mashed potatoes then top with a generous portion of the onion gravy.