Prepare the base : Place one puff pastry sheet on baking parchment directly on your baking tray. This prevents damage when moving the tart later.

Evenly spread 3-4 tablespoons of pesto, leaving a 1 cm border around the edge.

Sprinkle a thin layer of Gruyère or cheddar, just enough to add richness without weighing down the pastry.

Gently place it over the first, pressing lightly along the edges to seal.

Set a small glass in the center as a guide. Cut the pastry into 4 quarters, then cut each quarter into 4, you should have about 16 strips (more if your pastry is larger).

Carefully twist each strip twice to form the sun rays. Don’t pull too hard to avoid tearing the base.

Mix the egg yolk with cream, brush evenly over the pastry, and sprinkle with sesame and nigella seeds.

Preheat oven to 180°C (350°F).

Bake on the second rack from the bottom at 150°C (300°F, bottom heat only) for 15 minutes to crisp the base.

Raise temperature to 180°C (350°F, fan setting) and bake another 10-12 minutes, until golden and puffed.