Preheat oven to 350 degrees fahrenheit and line a baking sheet with parchment paper or a silicone baking mat.
Allow spinach to warm to room temperature and mix with parmesan cheese, milk and flour until well combined.
Knead dough into ball and roll onto a heavily floured surface (the dough is very sticky) 1/4 inch thick and cut with you cookie cutter of choice.
Bake for 10 to 15 minutes, until the cheese is bubbled and slightly browned.
Cool and refrigerate.
Makes 2 to 3 dozen stars.