Filling
1. Heat Plugrá Butter in skillet; add onions and sauté over low heat until tender. Add garlic and sauté an additional 1 to 2 minutes, or until tender.
2. Squeeze thawed spinach to remove excess moisture. Combine with sautéed onion mixture and stir until blended.
3. Combine beaten egg, feta cheese, Parmesan cheese, nutmeg, garlic pepper seasoning, salt and crushed red pepper in a bowl and stir to blend; add spinach mixture and stir until blended.

Assembly
1. Preheat oven to 350°F.
2. Unroll phyllo dough and cover with plastic wrap and a lightly dampened towel, while working.
3. Arrange 1 sheet of phyllo dough on a flat work surface (with 9-inch wide side nearest you). Brush lightly with melted Plugrá Butter; repeat with 2 more sheets of phyllo dough. Cut the phyllo dough lengthwise into 3-inch wide strips.
4. Place 1 heaping tablespoon of spinach filling in lower left side of each strip; Fold the corner over the filling to form a triangle. Continue to fold the triangle, similar to folding a flag, until you reach the end of the strip. Repeat with remaining 2 strips. Brush outer surfaces of phyllo triangles lightly with butter and arrange on a baking sheet lined with parchment paper.
5. Repeat with remaining phyllo dough.
6. Bake spanakopita uncovered at 350°F for 25 to 30 minutes or until golden.