The phyllo dough shatters into impossibly flaky layers — so buttery and crisp you can hear it across the table. Inside, the spinach-feta filling is ridiculously creamy with perfect salty feta, earthy spinach, and warm hints of dill and nutmeg. This is authentic Greek pastry done right — rich, herbaceous, and light all at once.
Preheat oven to 350°F (175°C). In a large skillet over medium heat, warm 2 tbsp olive oil. Sauté yellow onion and green onions until soft and translucent, about 5 minutes. Remove from heat and let cool.
In a large mixing bowl, combine the chopped spinach, sautéed onions, crumbled feta, ricotta, eggs, fresh dill, nutmeg, salt, and pepper. Stir until the filling is cohesive and creamy.
Lay out the phyllo dough and cover with a slightly damp towel. Nick the Greek technique: Work quickly and keep unused sheets covered to prevent drying.
Brush a 9x13-inch baking dish with melted butter. Layer 8 phyllo sheets on the bottom, one at a time, brushing each sheet generously with melted butter or olive oil for authentic flakiness.
Spread the spinach-feta filling evenly over the bottom phyllo layers. Top with the remaining 8 sheets of phyllo, again brushing each with butter. Gently score the top layers into squares without cutting through. Bake for 45-50 minutes until the pastry is golden, crisp, and audibly shattering.
Let spanakopita rest 10 minutes. Slice along the scored lines and serve warm — layers will be flaky and filling creamy, just like Nick the Greek.