Heat the olive oil in a frying pan and fry the potato slices gently until beginning to colour on both sides. Remove from the pan and set aside.
In the same pan, gently fry the onion, garlic and carrots for 3-4 minutes, then add the chopped mutton. Season well with salt and freshly ground black pepper and fry for ten minutes, or until the mutton is tender and golden-brown.
In the same pan, heat the beef stock and red wine and simmer until reduced slightly. Stir in the butter.
Serve the mutton and carrot mixture in a serving dish, pour over the wine sauce and top with the fried potato slices.