8 med. to lg. potatoes
1 lg. separated egg
1 med. onion, diced
4 tbsp. butter
1/4 c. milk
1/4 c. water from potatoes
Salt and pepper to taste

Cut up potatoes and cook in salted water until soft. Cook diced onion in 1 tablespoon butter until soft and golden. Mash potatoes and moisten with remaining butter. Add milk and enough water from potatoes so potatoes are creamy and well mashed. Add salt and pepper to taste. Mix white of separated egg into potato mixture. Add cooked onion and mix well. Put into 2-quart casserole and use pastry brush to spread yellow of egg across top of mashed potatoes. Bake 1 hour in 350 degree oven.