Sue's Shepherd's Pie

Heat oil in large skillet over medium heat. Add onions and saute until soft. Add garlic. Cook 3-4 minutes, stirring. Add meat and brown. Lower heat and add oregano, Worcestershire sauce and vinegar. Season to taste. Stir in 1 cup of milk. Add tomato paste, stir, then add beef stock. Add peas and simmer for 10-15 minutes. Meanwhile, cook carrots in separate pot until just cooked. Drain and add to rest of ingredients. Put potatoes in pot of cold, salted water and bring to boil. Lower heat slightly and cook until knife pierces potato easily. Drain. Put remaining cup of milk and butter in microwave-proof dish and cook in microwave until melted. Mash potatoes, add melted butter and milk and stir thoroughly. Season to taste. Add cheese and stir. Heat oven to 325 degrees. Spoon meat mixture into a large, oven-proof dish (or four individual dishes). Spread evenly. Spoon mashed potatoes on top. Using a fork, spread potato across meat to edges of dish. Dot top with butter. Bake for about 40 minutes, or until top browns and meat juices begin to bubble. Remove from oven, cool slightly. Sprinkle with parsley and serve.