Ingredients

• 4 pounds unpeeled russet potatoes (about 5 large potatoes)
• 1 pound yellow onions (about 2 medium onions)
• 1/4 cup matzo meal
• 2 teaspoons kosher salt, plus more to taste
• 1/2 teaspoon freshly ground black pepper
• 2 large eggs, lightly beaten
• 1/4–1/2 cup (or more) vegetable oil
• 1/4 cup (or more) schmaltz (rendered chicken fat; optional)
• Apple sauce, for serving
• Sour cream, for serving
• Food processor with grating blade or box grater, 2 large wire cooling racks, 2 large rimmed baking sheets

Instructions

1. Preheat oven to 250°F. Set racks in upper and lower thirds of oven. Place wire cooling racks in the rimmed baking sheets and place in the oven.
2. Using a food processor with a grating insert, grate the potatoes and then the onions, transferring grated vegetables to a large bowl when the bowl of the food processor is filled. Alternately, use a box grater. Working in batches, place the potatoes and onions in a clean dishtowel and thoroughly wring out the excess liquid over the sink, then transfer the potato-onion mixture to a large bowl. The more liquid you remove, the crispier your latkes will be, so take your time and use several dish towels if necessary. Reserve the potato-onion mixture.
3. In another large bowl, whisk together the matzo meal, salt, and pepper. Add the eggs and whisk to combine. Add the potato-onion mixture and mix well.
4. In a large skillet over medium heat, melt equal parts schmaltz and oil (or oil only if omitting the schmaltz) until a scant 1/4-inch depth of fat is reached. Drop 2 tablespoons of latke mixture into the hot fat, spacing them 2 inches apart. Flatten latkes slightly using a spatula and cook, turning once, until crisp, golden brown, and cooked through, 3 to 4 minutes per side.
5. Transfer latkes to wire racks and season with salt; return to the oven to keep warm; season with salt. As you remove latkes from the pan, replace them with fresh spoonfuls of potato mixture to maintain oil temperature. Add additional schmaltz and/or oil around the edge of the pan as needed to maintain a scant 1/4-inch depth of fat.
6. Keep latkes warm in oven and serve hot with applesauce or sour cream.