01 - Preheat oven to 400°F. Line a rimmed baking sheet with parchment paper and set aside.
02 - Unroll the puff pastry onto the parchment-lined baking sheet. Using a sharp knife, score a ¾-inch border around all edges without cutting through the dough. Prick the center area repeatedly with a fork to prevent puffing. 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 with salt and pepper. Stir until the mixture is smooth and well blended. Spread the filling evenly across the pricked center of the pastry, staying within the scored border.
04 - Toss the trimmed asparagus spears with olive oil, a pinch of salt, and pepper. Lay the spears in a neat, even arrangement over the cheese filling, aligning them in parallel rows or a tight fan pattern.
05 - Transfer to the preheated oven and bake 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 from the oven and scatter fresh thyme leaves over the top. Allow the tart to rest for 5 minutes before slicing into portions. Serve warm or at room temperature.