This Classic Lemon Curd Tart is the perfect dessert to serve at a dinner party or for a special occasion. It combines a homemade shortcrust pastry, simple lemon curd filling and is finished with an optional toasted Swiss Meringue topping!
Mix the Flour, Icing Sugar and Salt in the bowl of your Food Processor. Add the cold Butter cut into small cubes, then pulse to blend until you get very small crumbs.
Add the Egg and blend until a dough starts to form. Remove from the food processor and bring the dough together into a ball (see note 1).
Place the dough between two sheets of baking paper and roll into a large, thin circle about 4 mm (1/8 inch) thick. Place the rolled pastry over a flat tray and leave in the fridge to rest and chill for at least an hour, or up to 24 hours.
Take out of the fridge and line the pastry inside a 25 cm / 10 inch perforated tart ring - or your choice of tart pan with removable bottom (see note 2). Dock the pastry then place back in the fridge for another hour - or up to 24 hours.
Preheat your oven on 160'C/325'F and place the pastry in the freezer in the meantime. Blind bake for 30 to 40 minutes or until golden and fully baked. Set aside to cool down completely.
Lemon Curd Filling
Zest and Juice the lemons. Place the juice in a small saucepan and set the zest aside. Heat up the Lemon Juice until it starts to steam and in the meantime, whisk together the Egg Yolks, Sugar and Cornstarch in a small heat-proof bowl.
Pour the warm lemon juice over the sugar/egg mixture while whisking, then transfer it all back into the saucepan. Cook on low to medium-low heat until the curd starts to thicken, continuously stirring. (see note 3)
Add the Butter a little bit at the time until all incorporated. Add the Lemon Zest then continue to cook for another 2 to 3 minutes (see note 4). If required, pour the cooked curd through a thin mesh sieve to remove any lumps.
Pour the hot curd inside the baked tart crust and spread it around with a small offset spatula. Place it in the fridge to chill and set for at least 2 to 3 hours (or overnight) or until the curd has set.
Swiss Meringue Topping (optional)
The meringue topping should be added as close to serving as possible.
Combine the Egg Whites and Sugar in a small heat-proof bowl. Place it over a small saucepan filled with a little bit of water (not touching the bottom of the bowl) and turn on low to medium low heat.
Continuously whisk for a few minutes. The mixture should have doubled in volume, be very frothy and the sugar should have dissolved (see note 5).
Transfer the mixture into the bowl of your stand mixer and whisk on medium to high speed until you almost reach stiff peaks (see note 6). Place in a piping bag and pipe over the tart to decorate (see note 7).
Toast the meringue with a kitchen torch then serve.
If the dough seems too dry (it does not stick when you press some crumbs together), add a little bit of very cold water, one teaspoon at the time. If it seems too wet, add a little bit more flour, one teaspoon at the time.
This recipe will give you enough pastry for a deeper but smaller tart pan like a regular 22 cm / 9 inch tart pan as well.
At this point, I recommend tasting the lemon curd and adjusting the sugar to your liking if needed. This curd is relatively tangy.
To know that the curd is cooked, dip the back of a spoon in the curd then draw a line with a finger. Tip the spoon down and check to see if the curd drips back down over the clear line. If the line stays clear, the curd is fully cooked and has thickened enough. The second option is to use a food thermometer; it is done when it reaches around to 82'C / 180'F.
If you rub the mixture between your fingers, you shouldn't feel any grains of sugar. You can also check the temperature to know it is ready; it should be around 70'C / 160'F.
The meringue should still be a bit soft to be easily piped over the lemon tart, so stop whipping just before you reach stiff peaks.
I use a "St Honoré Piping Tip" and piped the meringue into a crown shape, doing a criss-cross pattern all around the edges of the tart. But you can decorate it as you want with your choice of piping tip, or simply spread it around with a spatula. If you want to cover the full tart with the meringue, you should double the quantities of egg whites & sugar.