Preheat the oven to 375° F. Pour the vegetable oil into a 9x13-inch rectangular baking dish.
Grate the potatoes using the large holes on a hand grater or the shredding blade of a food processor. Transfer the grated potatoes to a colander and run cold water over the shreds, tossing by hand until they are thoroughly rinsed. (This rinses out excess starch and prevents them from turning dark.) Drain thoroughly then squeeze the shredded potatoes by hand to remove as much water as possible. Place in a large mixing bowl.
Grate or chop the onion very fine and add to the shredded potatoes. Beat the eggs with the salt and pepper, and add to the potato mixture along with the chopped parsley and the matzoh meal. Mix thoroughly.
Place the baking dish containing the vegetable oil into the oven and let it heat for about 5 minutes -- or until very hot. Remove the baking dish from the oven and pour about half of the hot oil into the potato mixture, stir well, then spoon the potato mixture into the hot, oiled baking dish. Bake for 50 to 60 minutes or until the top of the kugel is golden brown and crisp.