Thaw the phyllo dough according to package instructions and thaw and drain the spinach.
Preheat the oven to 400 degrees F and begin heating the spinach and onion in a pan over medium heat in a tablespoon of oil. Cook until the onion is translucent, then add the garlic and cook a minute longer. Remove the spinach mixture from the heat and let cool while you prepare the dough cups.
Grease and line 10 places in a muffin tin. Then, using a biscuit cutter or mason jar ring, cut out 10 circles from the dough. Roll them out to size so that when placed in the muffin tin, the edges cover the side of the mold. Place each dough in the prepped muffin tin.
Once the spinach has cooled to the touch, add in the rest of the ingredients, stir until combined, and fill the dough cups.
Bake for 15-20 minutes until the dough has browned. Remove from the oven and let cool for 10-20 minutes and enjoy!