Trim the meat into neat even-shaped pieces. Skin the kidneys, remove the cores and cut the kidneys in halves. Soak in cold water for 5 min. Curl the bacon into rolls, prick the sausages and peel the mushrooms. Brush them all (including tomatoes) with oil or butter and thread on to 6 skewers with a bay leaf at each end. Grill for 10–15 min., turning as required. Serve on their skewers and, if liked, on a bed of risotto (rice cooked in stock in a casserole until stock is absorbed).