Start by gathering the filling components. Combine the thawed spinach, chopped artichokes, cheeses, mayo, and seasonings in a bowl. Stir until everything is well blended, forming a creamy mixture that smells divine.
Roll out your puff pastry on a floured surface. Spread the prepared filling in an even layer across the top, making sure all edges are covered. Starting from one end, roll the puff pastry tightly into a log. Seal the edge with a brush of beaten egg to keep it intact.
Slice your log into evenly sized rounds, about ½ inch thick. Lay them flat on a parchment-lined baking sheet. Brush the tops with more egg wash to achieve that golden-brown finish. Pop them into a preheated oven at 375°F (190°C) and bake for 15-20 minutes. Once done, remove them from the oven, garnish with parsley or basil, and serve warm.