A casserole dish which brings welcome variety to the menu and is nutritious and attractive, has four chief ingredients:  tomatoes, butter, onions and potatoes.  Dip tomatoes, which must be firm, into boiling water, skin and cut into quarters.  Put a layer at the bottom of a casserole, then a layer of onions, next a layer of sliced potatoes.  Sprinkle with chopped parsley, salt and pepper.  Repeat layers until vegetables are used up.  Barely cover with meat stock, close casserole and place in hot oven until boiling.  Lower gas and keep contents at simmering point.  The flavor is best brought out if served with cauliflower or spinach.