Preheat your oven to 200°C (400°F). While the oven heats, toast the slivered almonds in a dry skillet over medium heat for 2-3 minutes, stirring frequently until fragrant and golden—this brings out their natural oils and crunch. Set aside to cool slightly. Measure out all remaining ingredients and have them ready near your work station, including trimming the asparagus spears to roughly 5-inch lengths so they fit neatly on the pastry.

In a small bowl, whisk together the egg yolks and crème fraîche until smooth and well combined. Add the turmeric, lemon zest, garlic powder, nutmeg, salt, and black pepper, whisking until the spices are evenly distributed and the mixture has a pale golden hue. Stir in three-quarters of the freshly grated parmesan, reserving the remainder for topping. I find that freshly grated parmesan melts much more smoothly than pre-shredded cheese, which contains anti-caking agents that can affect the texture.

Roll out the puff pastry on a lightly floured surface to about 1/8-inch thickness. Transfer it to a baking sheet lined with parchment paper. Using the back of a knife, gently score a border about 1cm from the edges all the way around—this creates a frame that will puff up while the center stays flatter for the topping. Be careful not to cut all the way through the pastry, just mark it lightly.

Spread the creamy custard mixture from Step 2 evenly over the pastry, staying within the scored border line so the frame can puff up around the filling. Arrange the trimmed asparagus spears in neat parallel lines across the custard, spacing them evenly. Sprinkle the reserved parmesan cheese over the asparagus, then scatter the toasted almonds from Step 1 across the surface. I like to arrange the asparagus tips all pointing the same direction for a more elegant presentation.

Bake the tart in the preheated 200°C oven for 20-25 minutes, until the pastry border is puffed and golden brown and the custard is set but still slightly creamy in the center. The asparagus tips should be tender and lightly caramelized at the edges. Watch toward the end of cooking—every oven is different, so start checking at 18 minutes.

Remove the tart from the oven and let it rest for 2-3 minutes. Scatter the fresh chervil over the top while the tart is still warm so it releases its aromatic oils slightly. Serve immediately while the pastry is at its crispiest.