Creating Spinach Feta Puff Pastry Bites is straightforward if you follow these steps:

1. Preheat the Oven: Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
2. Sauté Spinach: In a skillet, heat olive oil over medium heat. Add chopped spinach and sauté until it wilts, about 2-3 minutes.
3. Mix Filling: In a bowl, combine the wilted spinach, feta cheese, cream cheese, garlic powder, and black pepper. Mix until well blended.
4. Prepare Puff Pastry: Roll out the puff pastry sheet on a lightly floured surface. Cut it into squares, about 3×3 inches.
5. Fill Pastry: Place a spoonful of the spinach mixture in the center of each pastry square.
6. Seal Pastry: Fold the pastry over the filling to form triangles. Press the edges to seal, and use a fork to crimp the edges for extra security.
7. Egg Wash: Brush the tops of the pastry bites with the beaten egg to give them a golden color when baked.
8. Bake: Place the filled pastry bites on the prepared baking sheet. Bake in the preheated oven for 20-25 minutes or until golden brown.
9. Cool: Remove from the oven and let them cool for a few minutes before serving.

Following these steps will ensure you create perfect Spinach Feta Puff Pastry Bites that are sure to impress!