Cook potatoes in salted water to cover. Drain, cool and peel.
Mash in large bowl with butter, milk and season to taste with
salt and pepper. Set aside. Saute beef until browned, stirring
to keep meat crumbly. Season to taste with salt and pepper. Add
tomatoes, mushrooms, parsley, tomato paste, Worcestershire and
gravy. Stir to mix. Add peas and cook about 5 minutes. Turn mixture
into casserole.
Spread potatoes evenly over meat. Bake at 400 degrees 40 minutes
until top is crispy brown.