Sour cream and/or unsweetened applesauce, to serve
Set a wire rack on a foil-lined baking sheet and place next to stove. Peel the root vegetables and the onion. Using a box grater, coarsely grate vegetables and onion. Wrap mixture in a kitchen towel or several layers of paper towels and squeeze out as much liquid as possible.
Add grated mixture to a large bowl with the eggs, matzo meal, baking powder, and garlic powder. Season with salt and pepper. Stir well to combine.
In a 12-inch nonstick skillet, heat 4 tbsp oil on medium-high. Working in batches, add mixture to skillet in mounds to form pancakes (about 3 tbsp per latke), flattening slightly. Fry 2–3 min. per side, until golden brown. Transfer latkes to the wire rack. Season with salt to taste.
Repeat frying with remaining latke mixture, adding remaining 2 tbsp oil as needed. Serve with sour cream and/or applesauce.