Prepare a 22cm/8.6 inch tart tin

TART SHELL PREPARATION

Place flour, sugar, salt, cornstarch and butter in the bowl and knead with K paddle until the dough resembles sand

Add the egg and knead into a smooth dough. If too wet add a little more flour, if too dry add a splash of milk

Roll the tart dough out into a circle slightly larger than your tart tin (to have borders of at least 5 cm)

Line the tart tin with the pastry and trim the edges

Dock (poke) the base of the pastry with a fork and place in the fridge to chill for 1-2 hours

Preheat the oven to 180C. Place a piece of baking paper in the unbaked tart shell and fill it with baking beans

Blind bake the tart pastry for 30 minutes, then remove the baking beans and baking paper and bake for another 10-15 minutes, or until golden brown (if the edges are getting too dark, cover them with aluminium foil)

TART FILLING PREPARATION

Combine the cream cheese, ricotta/mascarpone, parmesan, milk and butter in a large heatproof bowl

Melt the cheeses over a double boiler, mix until smooth

Add the eggs, vanilla, cornstarch and sugar, and stir the mixture a few minutes until well mixed

Remove from heat and cover with cling wrap. Chill in the fridge for at least 1 hour until chilled.

Preheat the grill to 170C

Fill the baked tart shell with the cream cheese filling and smooth off the top

Bake the cheese tart for until the top hardens a bit, then lightly brush the top with the beaten egg yolk and bake further until lightly golden (approx 50 minutes; if still liquid, then keep baking)

Place the cake in the fridge to cool down (1h?).

TART TOPPING PREPARATION

Use a fine-meshed sieve to sprinkle as little as possible of icing sugar on top of the tart

Using a blow torch, torch the top of the tart until it is burnished: with an angle of 45 degrees, hold the torch not too close from the tart. Start from the center and make small circles towards the outside. It will take time before the sugar starts to caramelize. Keep the caramel quite clear colored, lightly brown.

Once the caramel has cooled, redo a second round of caramelizing, with the same process as above, this time reaching a bit darker shade of brown.

Keep it at room temperature for the caramel to slowly dry (5-10 minutes). DO NOT put in the fridge as the humidity will soften the caramel!!

More info about caramelizing: