Heat the oven to 200°F. Put a plate or small sheet pan in the oven so you have a warm place to hold the fritters as they finish.

In a small bowl, stir the Greek yogurt with 1 tablespoon of the lemon juice, a pinch of the salt, and 1 tablespoon of water. The sauce should be loose enough to spoon over the fritters. Set it aside.

Put the drained lentils near the stove. Keep the sliced scallions and crumbled feta nearby, and reserve a small handful of each for the final serving step.

Warm the lentils: Set a medium saucepan over medium heat. Add 1 tablespoon of the olive oil and about half of the scallions that are not reserved for serving.

Cook the scallions in the saucepan for 1 minute, just until they soften and smell sweet.

Add the lentils to the saucepan with 2 tablespoons of water, 1/4 teaspoon of the salt, and a few grinds of black pepper. Stir and cook for 3 to 4 minutes, until the lentils are hot all the way through.

Take the saucepan off the heat. Stir in 1 tablespoon of the lemon juice, cover the pan, and keep the lentils warm.

Mix the fritters: Put the grated sweet potatoes in a large bowl. Add the chopped kale, the remaining scallions except for the reserved handful, and about half of the feta.

Crack the eggs into a small bowl. Beat them with a fork until the yolks and whites are fully mixed.

Pour the beaten eggs into the large bowl. Add the flour, 1 teaspoon of the lemon zest, the remaining 1 teaspoon salt, and the black pepper.

Mix the fritter batter with a spoon or clean hands until the vegetables are evenly coated and the mixture holds together when you press a handful. It will look shaggy, but it should stay in a mound when squeezed.

Cook the fritters: Set a large nonstick skillet over medium heat. Add 2 tablespoons of the olive oil and let it heat until it looks loose and shiny.