Toast the pine nuts: In a dry skillet over medium heat, toast pine nuts 3–4 minutes, stirring, until golden and fragrant. Transfer to a plate to cool.

Prep the pastry: Heat the oven to 400°F (200°C). Line a baking sheet with parchment. Lightly flour your work surface and unroll the cold puff pastry into a rectangle about 10x12 inches.

Spread the pesto: Using an offset spatula, spread a thin, even layer of sun-dried tomato pesto over the pastry, leaving a 1/2-inch border on all sides. Sprinkle with Parmesan, toasted pine nuts, herbs, and a few grinds of black pepper.

Form the palmier shape: With the long side facing you, roll the left long edge toward the center, then roll the right long edge toward the center to meet it. You’ll have two tight spirals meeting in the middle. Gently press to adhere.

Chill for clean slices: Transfer the rolled log to the freezer for 10–15 minutes (or the fridge for 30) until firm but not frozen. Cold dough slices better and puffs higher.

Slice: Using a sharp knife, trim the ends, then slice into 1/2-inch pieces. You should get about 16–20 palmiers. Place cut-side up on the prepared sheet, spacing 2 inches apart.

Brush and season: Lightly brush the tops and edges with egg wash. Sprinkle a pinch of flaky salt over each for extra crunch.

Bake: Bake 14–18 minutes, rotating the pan halfway, until the palmiers are puffed and deep golden. If any centers unfurl, nudge them back with a spatula while hot.

Cool slightly and serve: Let rest 5 minutes on the sheet, then transfer to a rack. Serve warm or at room temperature.