01 - Preheat oven to 375°F. Line a baking tray with parchment paper and set aside.
02 - In a mixing bowl, combine the chopped artichoke hearts, spring onions, dill, parsley, grated Graviera cheese, Greek yogurt, one beaten egg, salt, and pepper. Stir until all ingredients are evenly incorporated.
03 - Lay one sheet of filo pastry on a clean work surface. Keep the remaining sheets covered with a damp kitchen towel to prevent them from drying out. Brush the sheet lightly with olive oil or melted butter. Place a second sheet on top and brush again, creating a two-layer stack.
04 - Cut the layered filo stack into 4 equal strips lengthwise. Place one heaping tablespoon of filling near one end of each strip.
05 - Fold the corner of the strip over the filling to form a triangle. Continue folding the triangle shape along the strip until you reach the end, sealing the filling inside. Repeat with remaining filo sheets and filling to make approximately 16 puffs.
06 - Place all folded puffs on the prepared baking tray. Brush the tops generously with egg wash to promote browning.
07 - Bake for 20 to 25 minutes until the pastry is golden brown and crisp to the touch.
08 - Allow the puffs to cool slightly on the tray before serving warm.