- LINE 2 sheet pans with paper towels.
- GRATE onion and potato. Wrap in cheesecloth and strain over a bowl, making sure to get out as much of the moisture as possible; set aside the bowl of potato water to allow potato starch to settle to bottom. Spread potato and onion out on a kitchen towel.
- DRAIN the potato water out of the bowl while carefully reserving the starch that is settled in the bottom of the bowl.
- TOSS onion, potato, egg, flour, salt and pepper in the bowl with the potato starch. Set aside for 10 minutes.
- MAKE SCHMALTZ: Remove skin and fat from chicken thighs (reserve meat for another use); cut the skin into thin strips and place in a saucepan with fat and water; cook on low (cooking low and slow allows the fat to render without the skin getting too dark and crispy too soon). Once the water and moisture in the fat and skin have cooked off, the fat will begin to brown. Add onion only when the skin has slightly browned and fat has rendered. Do not overcook the fat; it should remain yellow and clear. Strain the fat (schmaltz) from the skin and onion (gribenes).
- ADD oil and schmaltz to a large skillet to about 1/4 inch deep. (If you decide not to use schmaltz, replace it with an equal amount of oil.)
- SCOOP 1/4 cup potato mixture per latke into hot oil (do not crowd the pan). Fry for 4 to 5 minutes on each side. Remove cooked latkes with a slotted spoon and drain on paper towels.
- SERVE warm, topped with sour cream and applesauce and sprinkled with parsley.
*Schmaltz is rendered chicken fat, which adds an extra layer of flavor but is not necessary to have delicious latkes. You can use an equal amount of vegetable oil, duck fat or ghee as a substitute for Schmaltz. If you do make schmaltz you’ll also be able to enjoy gribenes – crispy chicken or goose skin crackling and fried onions – which makes it worth the time and effort.