Preheat oven to 350 degrees.
In a large skillet lightly coated with non-stick olive oil cooking spray, sautee spinach and minced garlic until spinach is wilted, approximately 2 minutes; set aside to cool.
In a large bowl, beat eggs together with salt and pepper; add feta cheese and stir.
Add spinach to egg mixture and stir to combine well.
Phyllo dough dries out quickly, but there’s an easy way to prevent that. After cutting dough (see steps below), cover with a piece of waxed paper and lay a very damp paper towel on top of the waxed paper. This will keep dough moist and avoid it drying out.
Prepare phyllo dough by cutting into 3-inch wide long strips (we use the rectangular-shaped box the dough comes in to measure the width – use a sharp knife or a pizza cutter to slice dough). Cover dough as instructed above.
Take 4-5 pieces of dough and lay it down on a clean surface; take a heaping tablespoon of spinach mixture and place on the end of the dough, leaving 1/2 inch of room to fold.
Fold dough in a triangle shape, brushing dough very lightly with butter every other fold. When you reach the end of the dough, brush once more with butter to ‘seal’ spinach pie. Repeat with all ingredients until pies are made.
Bake pies at 350 degrees for 20 minutes, flipping pies over after 10 minutes so they brown evenly on each side.
Allow to cool for 5 minutes before serving.
Make a double-batch! Wrap half of the pies individually in small fold-over sandwich bags, and store in a large air-tight container in your freezer for up to 2 weeks. This way you can bake just enough for your evening meal, or for a quick snack.