Rinse and pat dry the zucchini. Trim ends and cut into roughly 3”-long sections. Place each section on a cut side, then slice into ¼”-thick planks. From there, cut each plank into sticks, discarding the soft seeded parts. You should end up with about 9-10 ounces of zucchini sticks.
Slice the yellow onion into 1/16” half-moon slices and add to the zucchini. Sprinkle with 2 teaspoons of the kosher salt and toss well to coat. Place in a strainer and let rest for 1 hour.
After 1 hour, squeeze out as much liquid from the zucchini mixture as you can. Transfer to a bowl along with the egg, flour, and remaining ¼ teaspoon kosher salt. Stir the batter until well combined.
Heat a skillet over medium heat and pour in about ¼” of sunflower oil. When the oil is hot, spoon roughly ⅓ cup of the batter into the hot oil.
Press down with the back of the spoon to flatten the fritters into 3" rounds. Fry until just golden, flip, and cook the second side until just golden.
Remove the fritters from the skillet and place on a wire rack. Let rest while cooking the remaining fritters.
Once finished, briefly fry the fritters a second time until they are a deep golden color.
When lifting from the pan, drain off as much oil as possible. Divide the Fresno lentil puree between two bowls and top with 3-4 fritters each.
