Preheat oven to about 215 °F (420 °F/≈220 °C). Remove phyllo from fridge 1–2 hours before use to reach room temperature

Wring out chopped spinach thoroughly until dry. Mix it with onions, herbs, beaten eggs, feta, mint (if using), salt, and pepper until well combined

Keep most filo covered until ready. Take one sheet (long side facing you), brush with butter or oil, top with another sheet and brush again. Repeat until 3–4 layers stacked.

Spoon a line of filling along one long edge of filo stack. Roll loosely into a log starting from the filled side. Coil the log into a spiral in a greased baking dish or ovenproof skillet. Repeat to create 3 spirals, nesting them together in one continuous coil

Brush spiral top with remaining butter/oil. Sprinkle with nigella or sesame seeds if desired.

Bake 20–25 minutes until golden, crisp, and heated through

Let cool slightly before slicing into wedges. Serve warm or at room temperature.