01 - Preheat the oven to 400°F. Line a rimmed baking sheet with parchment paper and set aside.
02 - Unfold the thawed puff pastry onto the parchment-lined baking sheet. Using a sharp knife, lightly score a ¾-inch border around all edges without cutting through the dough. Prick the center area repeatedly with a fork to prevent puffing, then brush the scored border evenly with the beaten egg wash.
03 - In a mixing bowl, combine the softened goat cheese, crème fraîche, minced garlic, and lemon zest. Season generously with salt and pepper, then stir until the mixture is completely smooth and homogeneous.
04 - Spread the goat cheese filling evenly across the center of the pastry, staying within the scored border. Toss the trimmed asparagus spears with olive oil, a pinch of salt, and pepper, then arrange them in a neat, tight row over the filling.
05 - Bake on the center rack for 30 to 35 minutes, rotating the pan halfway through, until the pastry border is deeply golden and puffed and the asparagus is tender with lightly charred tips.
06 - Remove the tart from the oven and scatter fresh thyme leaves over the top. Allow it to rest for 5 to 10 minutes before slicing into portions. Serve warm or at room temperature.