Thick pastry flan super gourmand

Ingredients
For the pastry
250 g flour
125 g soft butter (not melted)
2 tablespoons sugar
1/2 teaspoon salt
60 ml water
For the flan
1.2 liters milk (preferably whole)
300 g sugar, divided into 2 x 150g
6 eggs
140 g cornstarch
30 cl full-fat cream
1 vanilla pod
Preparation
For the homemade shortcrust pastry
Mix flour, sugar and salt in a small bowl. Add the soft butter, cut into small pieces, and knead with your fingertips for a few minutes until you obtain a sandy mixture. Add the water and quickly form a ball of dough. Cover with film and refrigerate for at least 30 minutes.
Shortcrust pastry
After the 30 minutes, roll out the shortcrust pastry into a large, fairly thick disk (a little thicker than commercial shortcrust pastry, around 3mm) on a lightly floured work surface. Line a buttered pastry circle (20-22cm) with the dough, making sure it adheres well to the sides of the circle. Prick the pastry with a fork. Place the circle on a baking sheet (or oven tray) lined with baking paper (or better still, a baking mat). Set aside in the fridge while you prepare the flan mixture.
For the flan
In a large saucepan, pour in the milk, 150g sugar (half the sugar in the recipe), the seeds from the vanilla pod (split and scraped to remove them) and the vanilla bean. Mix and bring to the boil.
Meanwhile, whisk the eggs and remaining 150g sugar in a large bowl for 1-2 minutes. Add the cornstarch (preferably sifted), then the cream, and whisk until smooth.
When the milk boils, turn off the heat, remove the vanilla pod and pour the milk into the large bowl (containing the rest of the ingredients) in batches, whisking well. Return the mixture to the large saucepan and cook over medium heat, stirring constantly, until the mixture thickens as shown in the photo.) Turn off the heat and leave to cool for 15-30 minutes.
Recipe Thick pastry flan
Preheat oven to 210°.
Preheat oven
Remove baking tray and ring from fridge and pour mixture inside. Smooth the surface.
Recipe Thick pastry flan
Place in the oven at 210° for 20 minutes, then increase the temperature to 240° and bake for a further 10 minutes or so. The flan should be golden-brown and still quivering when removed from the oven. Don’t hesitate to cover the flan at the end of baking if it’s browning too quickly, or to continue baking for a few minutes if it’s too pale. Once out of the oven, let the flan cool to room temperature before unmolding, then set aside in the refrigerator for at least 4 hours, ideally overnight (or 12h).