French Citrus Gold: Velvety Tarte au Citron to Shine

<h3>For the Sablée Dough (Crust)</h3><p>In a food processor, combine the wheat flour, powdered sugar, salt, and lemon zest (if using). Add the cold butter cubes and pulse until a coarse meal texture forms. The professional technique is not to overprocess the dough.</p>

<p>Add the beaten egg and pulse again, just until the dough starts to come together. Avoid overworking the dough, as this can make it tough. Form a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.</p>

<p>On a lightly floured surface, roll out the dough with a rolling pin until you get a circle of approximately 3mm thickness, larger than your tart pan (24-26cm in diameter). The secret of this recipe is to keep the dough cold throughout the process.</p>

<p>Carefully transfer the dough to the pan, pressing it gently into the sides and bottom. Cut off the excess dough from the edges. Pierce the bottom with a fork and place in the freezer for 15 minutes.</p>

<p>Preheat the oven to 180°C. Line the frozen crust with parchment paper and fill with pie weights (or dried beans). Bake in a preheated oven for 15-20 minutes (blind baking). Remove the weights and paper, and bake for another 5-10 minutes, until lightly browned. Let it cool completely.</p>

<h3>For the Lemon Curd</h3><p>In a heatproof bowl, mix the eggs, egg yolks, refined sugar, lemon juice, and lemon zest. The most important tip is to use only the yellow part of the zest, avoiding the bitterness of the white pith.</p>

<p>Place the bowl over a bain-marie (without the water touching the bottom of the bowl), stirring constantly with a wire whisk. Cook for 10-15 minutes, or until the cream thickens enough to cover the back of a spoon. Do not stop stirring to prevent the eggs from cooking.</p>

<p>Remove from the heat and strain the cream through a fine sieve to remove any pieces of cooked egg or zest, ensuring a velvety texture. The short answer is: straining is essential for silkiness.</p>

<p>Add the cubed butter, one cube at a time, and beat vigorously with a wire whisk or hand mixer until the butter is completely incorporated and the cream is smooth and glossy. This step provides creaminess and shine.</p>

<p>Pour the lemon cream into the already baked and cold sablée crust. Refrigerate for at least 4 hours, or ideally overnight, so that the cream sets completely. This cooling time is crucial for the texture.</p>