How to Make It
In a bowl, stir together the shredded squash, onions, egg and matzoh meal. Season to taste with salt and pepper.
Heat 1/4-inch of oil in a large heavy skillet and heat over moderate heat. Working in batches, drop heaping tablespoons of the squash mixture into the hot oil, flattening slightly with the back of the spoon. Fry until the latkes are golden-brown and crisp on both sides, carefully flipping halfway through, 6 to 8 minutes. Using a slotted spoon, remove the latkes from the oil and drain on a paper towel–lined rack. Continue with the remaining squash mixture.
Stir together the sour cream and chives in a small bowl. To serve, place a small dollop of the sour cream on each latke and sprinkle with flaky sea salt and freshly ground black pepper.