01 - Preheat oven to 375°F. Line a baking sheet with parchment paper and set aside.
02 - In a mixing bowl, combine the cooked chicken, softened cream cheese, green onions, garlic powder, onion powder, salt, pepper, and parsley. Mix until all ingredients are evenly incorporated.
03 - Unroll the crescent dough and separate into 8 triangles. Spoon an equal portion of the chicken mixture onto the wide end of each triangle. Roll each triangle from the wide end toward the point, tucking in the sides to seal and form a pillow shape.
04 - Place the filled pillows seam-side down on the prepared baking sheet, spacing them evenly. Brush the tops with melted butter for a golden finish.
05 - Bake for 20 to 22 minutes, or until the pillows are golden brown and cooked through.
06 - While the pillows bake, melt 2 tablespoons of unsalted butter in a saucepan over medium heat. Add the flour and whisk continuously for 1 minute to form a roux.
07 - Gradually pour in the whole milk while whisking constantly to prevent lumps. Continue cooking and whisking for 3 to 4 minutes until the sauce thickens and coats the back of a spoon.
08 - Remove the saucepan from heat. Stir in the grated Parmesan cheese, salt, black pepper, and nutmeg until smooth and creamy. Fold in the chopped parsley.
09 - Arrange the warm chicken pillows on plates and ladle the creamy Parmesan sauce generously over each one. Serve immediately.