For the latkes: Grate the beet, sweet potato or sunchokes into a medium bowl. Grate the potato and onion into the same bowl. Transfer the mixture to a cheesecloth or clean kitchen towel and squeeze out all of the liquid. Really squeeze hard! The more moisture you can get out now, the crispier the latkes will be. In a medium bowl, mix together the squeezed-out mixture with the eggs, flour, kosher salt, and pepper until thoroughly combined.
In a medium nonstick skillet, heat 2 tablespoons of the grapeseed oil over medium-high heat. Divide the latke mixture into equal portions. Place 3 latkes in the skillet at a time. Keep them spaced out and don't overcrowd. I like to press down a little with the spatula to flatten the latke a bit after flipping to get it a little thinner, so that it's extra crispy. Fry until golden and crispy around the edges, 2 to 3 minutes. Carefully flip the latkes and fry the second side until crisp, pressing down with a spatula as it cooks, another 2 to 3 minutes. When the latkes are done and dark golden all over, place on a paper towel lined plate and season with sea salt. Repeat with the remaining 2 tablespoons grapeseed oil and latke mixture. Transfer to a serving plate. Serve with either Chive Sour Cream, Roasted Lemons, applesauce, or all three, and mint.
Chive Sour Cream:
In a medium bowl, combine the sour cream, chives, mint, and a generous pinch of salt. Mix thoroughly and set aside.
Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper.
Place the lemon slices in a single layer on the baking sheet, drizzle with the olive oil, and season with the salt. Roast until lightly golden, about 5 minutes. Set aside.