For the beef filling, heat a tablespoon of oil in a pan. Fry the beef, onion, carrots, beef stock, thyme, tomato paste, pepper and 1/4 water with cornflour until fairly thick but not dry. Put peas in till cooked. Dish into a Pyrex container and keep cool.
For the mash potato topping, boil potatoes until cooked. Remove skin and mash with butter, egg, mayonnaise, cream, pepper, salt and seasoning. Mash until creamy (do not blend).
Pipe on top of cooked beef and sprinkle with cheese on top and grill for 5 to 10 minutes until top is golden brown. Serve.
•The above recipe can serve 5 to 6 persons. For 2 you can just cut the recipe in half and for the mash potatoes, you don't have to be exact--just adjust how thick you want the potato topping to be or if you want more beef than potato.