Peel then shred potatoes. Put shredded potatoes in a potato ricer and squeeze out the water from potatoes. Toss with the onion, add salt and pepper. Heat grease in heavy skillet. Pack potatoes firmly in skillet, leaving 1/2 inch space around edges. Cook over low heat 10 to 15 minutes or until bottom has brown crust. Cut into 4 sections and carefully turn(only once). Add 1 T. more grease and cook another 10 to 15 minutes if necessary Very crispy cooked this way.