Preheat your oven to 180°C (350°F). In a large pan over medium heat, add a drizzle of olive oil, then add the chopped onion and cook until soft, about 5 minutes. Add the garlic and cook for an additional minute until fragrant.

Add the chopped spinach to the pan with the onions and garlic. Sauté until the spinach is wilted and any moisture has evaporated, about 5-7 minutes. For frozen spinach, ensure it is well-drained before adding to avoid excess liquid. Set aside to cool slightly.

In a large mixing bowl, combine the crumbled feta, ricotta (if using), and green onions. Add the cooked spinach mixture to the bowl, followed by the chopped dill and parsley. Season lightly with salt (as feta is salty) and pepper. Stir well to combine.

Add the beaten eggs to the spinach and feta mixture, stirring until everything is well blended. The eggs will help bind the filling, giving the pie structure when baked.

Prepare a baking dish (approx. 9x9 inches) by lightly greasing it with olive oil or melted butter. Layer the first sheet of phyllo dough, allowing it to overlap the edges of the dish slightly. Brush with olive oil or butter, then repeat this process with four layers of phyllo, brushing each with oil.

Spread the spinach and feta filling evenly over the prepared phyllo layers, smoothing it out with a spatula. Fold any overhanging phyllo dough edges over the filling for a neat edge.

Layer the remaining four sheets of phyllo over the filling, brushing each sheet with oil or butter as you layer. Tuck the edges down along the sides to enclose the filling. Use a sharp knife to score the top layer of phyllo into squares or diamonds, making it easier to cut when baked.

Bake the spanakopita in the preheated oven for 45-50 minutes, or until the phyllo is golden brown and crispy. Allow it to cool slightly before serving. Serve warm, garnished with a sprinkle of fresh dill if desired, alongside a simple Greek salad or tzatziki for an authentic touch.