Lemon tart with Italian meringue and a hint of thyme

This is the most important step for a pure taste. Prepare a paste from 2 tablespoons of baking soda and a little water. Scrub each lemon thoroughly with this paste using a soft vegetable brush. Then rinse the lemons under running water and blanch them by pouring boiling water over them in a bowl for about 1 minute. Rinse again under cold water and dry thoroughly with a paper towel. This process removes wax, pesticides, and other impurities from the skin.

In a large bowl, sift the all-purpose flour and powdered sugar. Add a pinch of salt. Take the very cold butter (125g) out of the fridge, cut it into small cubes (about 1x1 cm), and add it to the flour. Using a knife or a special pastry cutter, vigorously chop the butter with the flour until the mixture resembles wet sand or coarse crumbs. The goal is to warm the butter as little as possible with your hands.

Add one egg yolk (20g) and, if using, chopped fresh thyme leaves. Now quickly knead the dough with your hands, just until the ingredients come together into a uniform ball. Do not knead for too long! The longer you knead, the more gluten develops, and the dough will be hard instead of crumbly after baking. Flatten the finished dough into a disk and wrap it in plastic wrap.

Place the dough wrapped in foil in the refrigerator for at least 30 minutes, preferably for an hour. Chilling the dough is absolutely crucial. It allows the butter to firm up again, which prevents the dough from shrinking during baking and ensures its perfect flakiness.

Preheat the oven to 190°C (fan). Take the dough out of the fridge. On a lightly floured surface, roll it out into a circle larger than the tart pan (about 28 cm) and about 3-4 mm thick. Carefully transfer the dough to the tart pan (24 cm in diameter, preferably with a removable bottom), by rolling it onto the rolling pin. Firmly press the dough into the bottom and sides of the pan, using your fingers. Trim any excess dough with a knife or by rolling a pin along the edge of the pan. Prick the bottom densely with a fork.

Place a piece of parchment paper in the cake pan, and pour weights on top – special ceramic balls, dry beans, or peas. The weights will prevent the edges from sliding down and the bottom from puffing up. Put the pan in the preheated oven and bake for 15 minutes.

After 15 minutes, carefully remove the pan from the oven. Grabbing the edges of the parchment paper, lift it out along with the weights. Place the tart back in the oven and bake for another 10-15 minutes, until the bottom is dry and lightly golden. Remove from the oven and let it cool completely on a wire rack.

Grate the zest from 3 previously washed lemons using a fine grater (only the yellow part, the white part is bitter). Squeeze the juice from all 4 lemons – you should get about 150 ml of juice. In a metal or glass bowl, place 3 whole eggs and 2 additional yolks. Add 150g of fine sugar. Set aside the separated egg whites (a total of 3) in a separate, ideally clean bowl – they will be needed for the meringue.

Using a whisk, thoroughly mix the eggs, egg yolks, and sugar in a bowl until the ingredients are combined and the mixture becomes smooth and slightly fluffy. You don't need to beat them into a foam; just mix vigorously for about a minute. Then add the grated zest and squeezed juice from the lemons. Mix again.

Prepare a water bath. Pour water into a pot to a height of about 3-4 cm and bring to a boil. Reduce the heat so that the water is just gently simmering. Place a bowl with the egg-lemon mixture on top of the pot (the bottom of the bowl should not touch the water). While constantly whisking, heat the mixture for about 8-10 minutes, until it thickens noticeably and has a pudding-like consistency. The finished cream should coat the back of a spoon.

Remove the bowl from the pot. Cut the cold butter (80g) into cubes and add it in batches to the hot cream, stirring constantly until the butter is completely melted and combined with the mixture. Adding cold butter at the end will give the cream a velvety smoothness and shine.

To remove any potential lumps and lemon zest, strain the still hot cream through a fine mesh sieve into a clean bowl. Cover the surface of the cream with plastic wrap so that it touches the surface – this will prevent a skin from forming. Set aside to cool completely, then refrigerate for at least an hour to set.

In the bowl of a mixer, place the 3 reserved egg whites. Make sure the bowl and the whisk attachment are perfectly clean and degreased (you can wipe them with a cotton pad soaked in vinegar or lemon juice). Start beating the egg whites on low speed. When they start to foam, increase the speed to medium and beat until a thick, white foam forms, but not yet completely stiff (the so-called 'soft peaks').

Meanwhile, while the egg whites are being whipped, place 200g of fine sugar and 50ml of water in a small saucepan with a thick bottom. Heat over medium heat, stirring only until the sugar dissolves. Then stop stirring and cook the syrup until it reaches a temperature of 118-121°C (the 'soft ball' stage). If you don't have a thermometer, after about 5-7 minutes of cooking, dip a teaspoon into the syrup and then into cold water – a soft ball should be able to be formed from the syrup.

When the syrup reaches the right temperature and the egg whites are whipped to a thick foam, reduce the mixer speed to the minimum. Very slowly, in a thin stream, pour the hot syrup into the whipped egg whites, aiming for the space between the mixer attachment and the bowl's wall. Be careful not to let the syrup hit the whisk directly, as it will splatter around the bowl and harden.

When you pour in the entire syrup, immediately increase the mixer speed to maximum and beat the meringue continuously for the next 8-10 minutes. The meringue is ready when the mixing bowl feels completely cold to the touch, and the meringue itself is thick, glossy, and forms stiff, sharp peaks.

Take the chilled lemon cream out of the fridge. Transfer it onto the completely cooled shortcrust base and spread it evenly using a spatula or spoon.

On top of the cream, spread the prepared Italian meringue. You can do this with a spoon, creating artistic, irregular patterns and 'waves', or use a piping bag with a decorative tip (e.g., star-shaped) to create more regular rosettes.

Using a kitchen torch, caramelize the meringue, moving the flame a few centimeters away from its surface until the peaks turn a beautiful golden-brown color. If you don't have a torch, place the tart in an oven preheated to 220°C with the grill function on (heating from above) for 1-2 minutes, keeping a close eye to ensure the meringue doesn't burn.