Preheat the oven to 350 degrees F.
Thoroughly squeeze any excess water from the thawed spinach, removing as much liquid as possible. Coarsely chop
Melt 1 tablespoon butter in a large skillet over medium-high heat. Add the garlic and cook until fragrant and golden brown. Add the spinach
and nutmeg, sauteing for 1 to 2 minutes. Remove from the heat and mix in the feta, lemon juice
, cracked black pepper and egg
to thoroughly combine. Allow the filling to cool.
the remaining butter over medium heat in a small saucepan
. Cool slightly. Cover the stack of phyllo sheets with a clean damp kitchen towel.
Working with the long side of the phyllo sheet nearest you, take 1 sheet from the stack and brush the entire surface with butter. Top with another phyllo sheet, brushing with more butter. Cut crosswise into five 2 1/2 to 3-inch strips.
Place 2 teaspoons filling in the corner of each strip. Just like you would fold a flag, fold the corner of phyllo over to enclose the filling, forming a triangle, and continue folding the entire strip. Ending with the seam-side down, place the triangles on a large baking sheet and brush the tops with butter.
Follow the same steps with the remaining ingredients.
Space evenly on a sheet tray and bake until golden brown, about 25 minutes. Remove from the oven and transfer to a wire rack to cool slightly.