Step 1

Preheat oven to 300°. Line a sieve with 2 layers of paper towels; set over a large bowl. Remove stems and greens from beets; set aside. Scrub beets and potato, then grate on the large holes of a box grater into prepared sieve, followed by onion. Season with salt and toss well. Let vegetables sit at least 25 minutes.

Step 2

Meanwhile, finely chop reserved beet stems and greens. Heat 2 Tbsp. oil in a large skillet over medium-high. Add greens, season with salt, and cook, stirring occasionally, until wilted and starting to stick to pan, about 5 minutes. Transfer to a bowl and let cool. Wipe out pan; reserve.

Step 3

Working with a large handful at a time, squeeze grated vegetables to expel as much liquid as possible, transferring vegetables to a medium bowl as you go; discard liquid. Mix in eggs, panko, cornstarch, coriander, cumin, and 1½ tsp. salt.

Step 4

Heat 2 Tbsp. oil in reserved skillet over medium-high. Working in batches and adding more oil between batches if needed, scoop three ¼-cupfuls of vegetable mixture into pan and flatten into thin pancakes. Cook until browned, about 3 minutes per side. Transfer to a wire rack set inside a rimmed baking sheet and keep warm in oven until ready to serve. If you notice your beet mixture giving off a lot of moisture as it sits, you can add a bit more cornstarch and squeeze before adding to the pan.

Step 5

Meanwhile, squeeze juice from a lemon half into beet greens. Add yogurt and dill and mix well; season with salt and pepper. Slice remaining lemon half into wedges.

Step 6

Serve fritters with beet greens yogurt and lemon wedges.