Sesame seeds and / or poppy seeds, to top (optional)
Fresh basil, to serve (optional)
Preheat oven to 375°F. Line a baking sheet with parchment paper.
Roll out one sheet of puff pastry with a rolling pin to form large (at least 10″x10″) square. Use a large bowl (about 10″ across) to cut out a clean, large circle. Repeat for the other puff pastry sheet. Set aside.
Mix the ground chicken, pesto, 1 whole egg, garlic, breadcrumbs, Parmesan cheese, salt and pepper together until well-combined to create the filling.
Gently transfer one of the puff pastry circles to the prepared baking sheet. Spoon the chicken mixture onto the puff pastry and smooth out to create an even ring with a 3/4 inch border around the edge to leave room for sealing the dough. Place the brie round (with rind intact) in the center.
Cover with the remaining puff pastry round. Use a bowl that’s just slightly bigger than the brie round to firmly press the dough down surrounding the brie.
Gently pull dough the edges of the top puff pastry round so they meet the bottom puff pastry, and press together. If your dough isn’t sticking together well or feels somewhat dry, brush the edges with a bit of water before pressing together.
Use the tines of a fork to further seal and crimp the edges. Slice of any messy bits, if necessary.
Lift up the bowl to remove it. Prick around the indented valley between the filling and brie with a fork.
Slice the filled portion of the dough into 16 equal portions. Twist each portion so that the cut side is facing up, creating a sun-like appearance. Brush the entire pastry with beaten egg yolks. (If the yolks are too thick, add a teaspoon of water.)
Sprinkle the center with sesame seeds and / or poppy seeds, if desired, and bake until the chicken is baked through and the puff pastry is golden, about 35 minutes. The timing can vary a good amount, so make sure to keep an eye on it. Allow to rest for a few minutes before transferring to serve.
Slice off the top of the center of the puff pastry and brie rind, and pull off to expose the melted brie. Sprinkle with fresh basil and spoon over a tiny bit of additional pesto, if desired. Serve warm.