Chef Keller takes two classic childhood favorites and transforms them into grown-up culinary delights, all with the help of store-bought puff pastry. First, he dresses up chicken pot pie with Madeira, pearl onions, and baby carrots. Then, substituting puff pastry for graham crackers, he makes a to-die-for S'more with luscious, creamy homemade marshmallow. Roasted Chicken Pot Piek; S'more Burgers.