"Preheat oven to 400F.Cook potatoes in water until tender. Drain water and add butter, milk, salt and pepper and mash.Heat oil in a skillet then add the onions and carrots. Cook until softened. Add the meat and cook until browned, about 5 minutes. Add the peas and cook for another 10 minutes. Add the flour and cook, stirring, for another 2-3 minutes. Add the stock and spices and cook until thickened. Pour into casserole dish and top with the mashed potatoes. Cut some cold butter onto the top and put into the oven for 30 to 35 minutes, until it is heated through and the top is browned."