Italian Spinach and Ricotta Pie

Make filling: Place spinach in a skillet over medium heat and cook, stirring occasionally, until wilted, 3 to 5 minutes. Drain, squeeze dry, and chop finely.

Heat butter in a skillet over medium heat. Cook onion in hot butter until slightly softened, about 3 minutes. Add chopped spinach; cook and stir for 2 minutes. Transfer mixture to a bowl to cool slightly, about 5 minutes.

Stir ricotta cheese, Parmesan cheese, eggs, nutmeg, salt, and pepper into cooled spinach mixture until well combined. Set filling aside.

Preheat the oven to 350 degrees F (175 degrees C).

Make pie: Grease a 9-inch pie dish or tart pan with melted butter. Unwrap phyllo dough. Keep sheets covered with a damp cloth to prevent them from drying out.

Lay 1 sheet of phyllo over the prepared dish flush with the edge, so excess phyllo hangs over only one side. Press sheet gently into the dish and brush lightly with melted butter. Top with another sheet of phyllo at a slight angle to the first one. Continue in this manner with up to 12 sheets, brushing each with butter and working clockwise, laying each at a slight angle to the previous sheet.

Spoon filling evenly into the phyllo-lined dish. Using the back of a spoon, make 6 indentations in filling, then carefully place 1 egg yolk in each. Season each yolk with salt and pepper and drizzle with a bit of melted butter.

Fold overhanging phyllo dough, one sheet at a time, into the center to cover filling, brushing each with butter. Brush the top of pie with butter.

Bake in the preheated oven until phyllo is dark golden brown, about 40 minutes. Remove and let cool slightly before slicing.