Pre-heat the oven to 180°C, 350°F, Gas Mark 4.
Fry the meat and onions in the oil until browned. Stir in the tomato purée, Bay Leaf, Cloves, 2 tsp of the crushed Peppercorns, salt, lager and stock. Bring to the boil, stirring. Transfer to a casserole dish, cover and cook for 1½ hours. Remove from the oven and discard the Bay Leaf.
Stir in the capers if using, half the lemon zest and cabbage. Cover and return to the oven for a further ½ hour.
Serve garnished with the remaining crushed Peppercorns and lemon zest.