Using the food processor, grate the potatoes and place in a large bowl. Toss with the onion, salt and pepper. In a large skillet, heat the bacon drippings. Place the potato mixture in the pan, press down, cover, and cook for 10 minutes. As the potatoes cook, give the pan a gentle shake to make sure they do not stick. Using a spatula, turn the cake over. Continue to cook until golden brown.
Recipe adapted from Jean Anderson, "The New Doubleday Cook Book"