1. Preparation
Preheat the oven to 375°F (190°C).
Defrost 1 package of phyllo dough in the refrigerator overnight or at room temperature for a few hours.
Rinse 500g of fresh spinach under cold water to remove any dirt. Chop it finely.
Finely chop 1 medium onion and 2-3 garlic cloves.
In a skillet, heat 2 tablespoons of olive oil over medium heat and sauté the onion until translucent, about 5 minutes.
Add the garlic and chopped spinach to the skillet, cooking until the spinach has wilted (about 5 minutes). Remove from heat and let cool.
In a large bowl, combine the cooled spinach mixture with 200g of crumbled feta cheese, 1 beaten egg, salt, and black pepper to taste. Mix well.
2. Assembly
On a clean working surface, lay out 1 sheet of phyllo dough and brush it lightly with olive oil.
Layer another sheet of phyllo dough on top and brush it again with olive oil.
Place a generous amount of the spinach and feta filling along one edge of the dough, leaving about 1 inch of space on the sides.
Fold the sides of the phyllo dough over the filling and roll it up from the edge to form a log shape. Repeat this process for the remaining filling and phyllo sheets.
3. Baking
Place the rolled spanakopita on a baking sheet lined with parchment paper.
Once assembled, brush the tops with more olive oil for a golden color.
Bake in the preheated oven for 25-30 minutes, or until the phyllo is crispy and golden brown.
Remove from the oven and let cool for a few minutes before serving.