This Spinach Feta Puff Pastry appetizer is flaky, buttery, and packed with flavor. The combination of tender spinach, creamy feta, and crispy golden pastry creates a savory treat that feels fancy but is so easy to make. Perfect as an appetizer, snack, or light meal!
Preheat the oven to 400°F. Dice the onion and transfer to a pan or skillet along with 1 Tablespoon butter. Cook on medium-high heat for 3-4 minutes. While the onions are cooking, mince the garlic and add them to the pan; saute for a minute then add the chopped spinach. Season with salt and pepper and cook until all the excess juice evaporates.
Transfer the spinach mixture to a large bowl. Add the chopped herbs and cheeses; gently mix to combine.
Roll out puff pastry sheets on a floured surface and cut into squares or rectangles (approximately 4x6-inches).
Spoon the filling onto the rectangles and fold the puff pastry to seal the filling inside. Seal the edges with a fork and cut a few slits in the tops or use a lattice cutter to create a lace design. You can also place the entire filling on one sheet then the other pastry sheet on top and cut into rectangles or small squares.
Transfer the pastries to a baking tray lined with parchment paper. Brush the tops with beaten egg and sprinkle with sesame seeds if desired.
Bake for 20-25 minutes, or until the pastries are golden brown.