Preheat oven to 350 degrees Fahrenheit.

Sauté chopped onion in olive oil until translucent. Set aside to cool.

Place spinach, cheese, and eggs in a large bowl. Add onions. Season with nutmeg, salt and pepper. Pour mixture into an 11-inch shallow pie dish or tart pan. Bake for 20 minutes.

Keep phyllo sheets covered with a damp paper towel. Working with one sheet placed horizontally across your work surface, brush with melted butter or spray with oil. Using your fingers, pleat dough on the right side, forming a fan. Starting at that end, pleat and turn dough into a spiral until it resembles a rose; place on top of the spinach filling, at the outer edge. Repeat with remaining pastry sheets and place around the edge of the pan. Use three roses for the center.

Brush the top of the phyllo with butter or oil. Bake for 20 to 25 minutes until golden.