Step 1

Whisk yogurt, lemon juice, and sugar in a small bowl to combine. Season with salt.

Step 2

Do Ahead: Yogurt can be made 1 day ahead. Cover and chill.

Step 3

Rinse lentils, then soak in 2 cups water at room temperature at least 1 hour and up to 12 hours. (Soaking the lentils makes them tender and a lot easier to blend.)

Step 4

Meanwhile, trim ends of zucchini and cut crosswise into 3 pieces about 2" long. Cut each piece lengthwise into ¼"-thick planks. Stack a few planks and slice lengthwise into ¼"-thick matchsticks (about the size of a skinny french fry). Transfer zucchini to a colander set in a medium bowl. Add onion and 1 tsp. salt and toss to combine. Let sit until vegetables look wilted and softened and about 1 Tbsp. liquid has released into bowl, 30 minutes to 2 hours. Gently pat dry with paper towels to remove any excess moisture.

Step 5

Drain lentils and transfer to a food processor. Add chile powder, turmeric, and ¾ tsp. salt. Pulse, scraping down sides, until a purée forms. Transfer to a medium bowl and add zucchini and onion, parsley, and lemon zest. Toss with a rubber spatula to combine.

Step 6

Line a rimmed baking sheet with paper towels; set a wire rack inside. Heat ghee in a medium cast-iron skillet over medium-high until a pinch of batter added to the pan sizzles and sputters. Using a large spoon, scoop out about ¼ cup batter, then use a second large spoon dipped in the hot ghee to carefully scrape into pan; flatten with ghee-coated spoon. Repeat to make 3 more fritters. Fry until deep golden brown underneath, about 3 minutes. Turn over with a wide slotted spatula and fry until deep golden brown on the second side, about 3 minutes. Transfer fritters to prepared rack to drain; season immediately with salt. Repeat with remaining batter (you end up with 8–10 fritters total).

Step 7

Transfer fritters to a platter. Serve with lemony yogurt alongside.