In a heated skillet, add butter or olive oil and sauté minced garlic for about 30 seconds until fragrant. Stir in chopped fresh spinach, along with salt, pepper, and nutmeg. Cook until wilted, about 2-3 minutes. Remove from heat and let cool.

Preheat oven to 190°C (375°F) and line a baking sheet with parchment paper. Roll out the chilled puff pastry until about 1/4-inch thick. If too soft, refrigerate briefly.

Spread the spinach mixture onto one half of the puff pastry, leaving a border. Sprinkle with Parmesan and mozzarella. Fold over the pastry and seal the edges.

Slice the filled pastry into 1-inch wide strips and twist each strip to create a spiral shape. Arrange on the baking sheet.

Whisk together the egg and milk for the egg wash. Brush the tops of each twist with the mixture and sprinkle with sesame or poppy seeds. Bake for 18-22 minutes until puffed and golden brown.

Remove from the oven and let cool slightly. Serve warm or at room temperature.