Sprinkle the grated zucchini with about 1 teaspoon of kosher salt. Let rest for 10 minutes or so to allow the salt to draw out moisture from the zucchini. Squeeze zucchini using a ricer or by hand.
Whisk the egg in a medium bowl. Add zucchini, scallions, flour, and pepper to taste. Mix well.
Heat olive oil in a sauté pan over medium heat. Scoop mounds of batter (about 2 tablespoons each) into the pan, pressing down lightly to flatten with a spatula.
Sauté for about 4 to 6 minutes on each side, till golden brown. Remove to a paper towel-covered plate to drain excess oil.
Salt and serve while hot, garnishing with sour cream or yogurt if desired.
