Asparagus and Gruyère Tart

Instructions

1. Prepare the pastry
   Preheat the oven to 200°C (400°F). On a lightly floured surface, roll out the puff pastry to fit a 35cm x 25cm (14-inch x 10-inch) baking sheet. Transfer to a parchment-lined baking sheet. Using a sharp knife, score a 2.5cm (1-inch) border around the edge without cutting all the way through. Prick the inner rectangle with a fork to prevent it from puffing up too much during baking.
2. Create the cheese base
   In a medium bowl, combine the crème fraîche, eggs, milk, Dijon mustard, salt, and pepper. Whisk until smooth. Spread this mixture evenly over the inner rectangle of the pastry, staying within the scored border.
3. Prepare the asparagus
   Blanch the asparagus in boiling salted water for 1-2 minutes until bright green but still crisp. Immediately transfer to an ice bath to stop the cooking. Once cooled, pat the asparagus dry with paper towels. In a small pan, heat olive oil over medium heat and sauté the shallot and garlic until translucent, about 2-3 minutes. Let cool slightly.
4. Assemble the tart
   Sprinkle two-thirds of the grated Gruyère cheese over the egg mixture. Distribute the sautéed shallot and garlic evenly. Arrange the asparagus spears in a neat pattern on top, alternating directions if needed. Sprinkle with the remaining Gruyère and fresh thyme leaves. Season with freshly ground black pepper.
5. Bake to perfection
   Bake in the preheated oven for 20-25 minutes, or until the pastry is golden brown, puffed around the edges, and the cheese is melted and bubbling. Rotate the baking sheet halfway through cooking for even browning.
6. Serve and enjoy
   Remove the tart from the oven and let it cool for 5 minutes before slicing. Serve warm or at room temperature as an elegant appetizer or light main course with a simple green salad.