01 - Preheat oven to 375°F. Line a baking sheet with parchment paper and set aside.
02 - In a mixing bowl, combine the chopped artichoke hearts, sliced green onions, grated Graviera cheese, Greek yogurt, dill, parsley, lemon zest, black pepper, and salt. Stir until all ingredients are evenly distributed.
03 - Lay one filo sheet flat on a clean work surface. Keep the remaining sheets covered with a damp kitchen towel to prevent them from drying out. Lightly brush the sheet with melted butter. Place a second sheet on top and brush again with butter. Repeat with a third sheet, creating a stack of three buttered layers.
04 - Using a sharp knife, cut the stacked filo lengthwise into three equal strips.
05 - Place approximately 1 tablespoon of filling near the bottom edge of each strip. Fold one corner over the filling to create a triangle. Continue folding the strip up in a triangular pattern, keeping the shape tight and even as you go.
06 - Place each filled triangle seam side down on the prepared baking sheet. Repeat the layering, cutting, and folding process with the remaining filo sheets and filling to yield 12 puffs total.
07 - Brush the tops of the puffs with melted butter or egg wash for a deeper golden color. Bake for 20 to 25 minutes until the pastry is crisp and golden brown.
08 - Allow the puffs to cool slightly on the baking sheet before serving. Best enjoyed warm.