Gather all ingredients.

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

Lightly oil a 9-inch square baking pan.

Heat 3 tablespoons of olive oil in a large skillet over medium heat.

Add the chopped onion, green onions, and garlic. Cook and stir until soft and lightly browned, about 5 minutes.

Stir in the spinach and parsley, cooking until spinach is limp and excess liquid has evaporated, about 5 minutes. Remove from heat and set aside to cool.

In a large bowl, combine feta cheese, ricotta cheese, and lightly beaten eggs until well combined.

Stir in the spinach mixture until evenly mixed.

Lay one sheet of phyllo dough in the prepared baking pan and brush lightly with olive oil.

Lay another sheet on top, and brush with olive oil. Repeat this step with two more sheets, allowing them to overlap the pan edges.

Spread the spinach and cheese mixture evenly into the pan. Fold any overhanging phyllo dough over the filling and brush with oil.

Layer the remaining 4 sheets of phyllo dough on top, brushing each with olive oil.

Tuck any overhanging dough into the pan to seal the filling.

Bake in the preheated oven until golden brown, about 30 to 40 minutes.

Cut into squares and serve while hot.