01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper and set aside.
02 - Heat olive oil in a skillet over medium heat. Sauté the minced garlic for about 30 seconds until fragrant, then add the chopped spinach. Cook for 2 to 3 minutes, stirring occasionally, until the spinach is fully wilted. Remove from heat and let the mixture cool slightly.
03 - In a mixing bowl, combine the sautéed spinach with crumbled feta, softened cream cheese, black pepper, and nutmeg. Stir until all ingredients are evenly incorporated and the mixture is well blended.
04 - Roll out the gluten-free puff pastry on a surface lightly dusted with gluten-free flour. Spread the spinach and feta filling evenly across the pastry, leaving a ½-inch border along one long edge to help seal the roll.
05 - Starting from the filled long side, gently but tightly roll the pastry into a log. Brush the bare edge with a little beaten egg to seal. Using a sharp knife, cut the log into 16 even slices.
06 - Place the pinwheel slices cut side up on the prepared baking sheet, spacing them about 1 inch apart. Brush the tops and exposed edges generously with the remaining beaten egg for a golden finish.
07 - Bake in the preheated oven for 20 to 25 minutes until the pinwheels are puffed and golden brown. Allow them to cool slightly on the baking sheet before serving warm or at room temperature.