Directions:
1. Melt butter over medium heat in a nonstick pan.
2. Add the onions and garlic and sauté until soft, about 2 minutes.
3. Add the spinach and cook, stirring until all the moisture has evaporated.
4. Transfer this mixture to a bowl and let cool.
5. Preheat the oven to 375 degrees.
6. Stir in the feta cheese, lemon juice, salt & pepper and set aside.
7. On a clean countertop, take one sheet of pastry, brush it with butter, and place another sheet on top.
8. Cut lengthwise into eight strips.
9. Place a teaspoon of filling on the bottom left corner of each strip. Fold over the right side to meet the left to form a triangle. Continue folding in this manner until you have reached the top.
10. Place on a parchment covered baking sheet. Brush each one with butter.
11. Bake for approximately 15 minutes, until golden brown and serve warm.