Ingredients
2 bunches fresh spinach, preferably a hearty curly-leaved variety (1 1/4 pounds), thick stems removed
1 teaspoon vegetable oil, such as safflower, plus more for frying
1 medium yellow onion, halved and thinly sliced (2 cups)
1/2 cup unbleached all-purpose flour
1 large egg, beaten
1/4 teaspoon freshly grated nutmeg
Kosher salt (we use Diamond Crystal) and freshly ground pepper
3 ounces feta, drained and crumbled
Zesty Tomato and Curried-Sour-Cream Dipping Sauces, for serving
Preparation
Bring 1/2 cup water to a simmer over medium-high heat in a large skillet or saucepan. Add spinach, cover, and cook until wilted and tender, 2 to 3 minutes. Drain in a colander. When cool enough to handle, squeeze out as much moisture as possible with your hands (or use a ricer to press out excess). Coarsely chop spinach and transfer to a large bowl.
Heat oil in a medium heavy-bottomed skillet, such as cast iron, over medium. Add onion and cook, stirring occasionally, until tender but no color has developed, about 6 minutes. Transfer to bowl with spinach and let cool completely.
Stir in flour, egg, nutmeg, 2 teaspoons salt, and 1/4 teaspoon pepper. Fold in feta. Form mixture into golf-ball-size rounds, then flatten slightly into 1-inch-thick patties. Transfer to a parchment-lined tray and refrigerate until cold, at least 2 hours or, loosely covered, up to 1 day.
Pour a scant 1/2 inch oil into skillet. Heat over medium until oil shimmers and bubbles form instantly around a breadcrumb dropped in (350°F on a deep-fry thermometer). Working in batches, fry, flipping once and adjusting heat as needed to maintain a level temperature, until crisp and golden brown, about 5 minutes.
Drain on a wire rack set over a rimmed baking sheet; keep warm in a preheated 200°F oven while frying the rest. Serve warm, with dipping sauces.
