Crispy potato latkes are more than just Hanukkah hash browns—they’re a crispy/creamy treat for everything from breakfast in bed to a midnight snack. Vegetable oil works great, but duck fat or (mmm!) schmaltz makes them extra awesome.
Preheat oven to 350 degrees F. Line a large mixing bowl with a clean dish towel. Position the box grater in the bowl and grate the potatoes and onion using the largest holes. Bundle the towel and wring out the excess water into the bowl. The more moisture you release, the crispier the latkes will be. Discard the liquid.
Heat duck fat, schmaltz, or oil in a large skillet over medium-high heat until shimmering (about 350 degrees F). Meanwhile, in a large bowl mix grated potatoes and onion with 2 eggs, flour, matzo meal, and salt until there’s no visible flour. If the mixture seems dry and it’s not holding together, add one more egg.
Using your hands, form the latke mixture into golf ball-sized balls, then flatten slightly into thick pancakes. Gently place them one at a time into the oil, which should bubble around the latke but not burn the edges. Fill the pan with just enough latkes so they don’t overcrowd the pan (you’ll probably get about a half-batch in). Fry until golden on one side, 1–2 minutes. Flip and fry the other side until golden, 1–2 more minutes.
Remove latkes to a wire rack fitted over a parchment-lined baking sheet. Finish cooking the inside by baking, 10–12 minutes.
Remove from the oven and sprinkle both sides with salt and pepper. Serve immediately with sour cream and applesauce.
Latkes reheat beautifully. To do so, store refrigerated in an airtight container. To warm, place latkes on a sheet pan and heat in 350 F oven until warmed through, 6–8 minutes.