In a large saute pan, over medium heat, add the oil. When the oil is hot, add the onions. Season with salt and pepper. Saute for 2 minutes. Finely chop the lamb. Add the lamb to the onions and saute for 1 minute. Dust the lamb with the flour and cook 2 minutes, stirring constantly. Stir in the tomato paste and cook for 30 seconds. Stir in the red wine and the veal reduction. Bring the liquid to a boil. Stir in the thyme, corn, peas and carrots. Season with salt and pepper. Reduce the heat to medium low and simmer for 10 minutes. Pour the mixture into a deep 9-inch oval dish. Place spoonfuls of the potatoes over the meat mixture. Dot the top of the potatoes with butter. Place in the oven and cook for about 30 minutes or until the potatoes are golden. Place a baking sheet under the dish in case the pie starts to bubble over. Remove from the oven and spoon onto serving plates. Garnish with parsley.