Ingredients
Equipment
Method
Lemon Custard Mix
- Whisk together the lemon juice, zest, whole eggs, egg yolks, sugar, and whipping cream until the mixture is completely homogenous and the sugar has begun to dissolve. Once combined, cover the bowl by pressing cling film directly onto the surface of the liquid to prevent a skin from forming or any fridge odours from being absorbed. Allow the custard to rest and infuse in the fridge for 24 hours alongside your pastry; this crucial cold infusion period deepens the citrus profile and allows any air bubbles created during whisking to rise and dissipate, ensuring a glass-smooth, bubble-free finish once baked.
Pâte Sucrée
- Into a stand mixer fitted with the paddle attachment, add the flour, chilled cubed butter, sugar, and salt. Begin mixing on a low speed to incorporate, gradually increasing the speed as the butter begins to break down. Continue to mix for approximately 5 minutes until the mixture achieves a uniform, sandy consistency and the butter has completely dissipated.
- Set the mixer to a low speed and add the egg, continuing to mix just until the moisture is absorbed and the dough begins to clump and come completely together. Promptly turn the dough out onto a lightly floured work surface and perform a gentle knead for approximately 20 seconds; this final hand-finish ensures the hydration is even and the dough is perfectly smooth without overdeveloping the gluten. Flatten the dough into a disc, wrap tightly in cling film, and allow it to rest in the fridge for 24 hours to fully hydrate the flour and relax the proteins, ensuring an easy roll-out with zero shrinkage in the oven.
Blind Baking
- Preheat your oven to 170°C (338℉) and thoroughly grease and flour your tart tin to ensure a clean release. On a lightly floured work surface, roll the chilled dough to a uniform 3–4mm thickness, then trim it into a 30cm diameter circle.
- Carefully lift and line the tart tin, gently pressing the dough into the base and into the fluted walls to ensure no air pockets remain. Trim any excess dough from the rim with a sharp knife for a professional, flush finish. To prepare for the blind bake, lay a couple of layers of heat-resistant cling film over the dough and fill it to the brim with rice or baking beans; allow the excess cling film to hang over the outer walls, neatly tucking it in to protect the edges of the pastry from over-browning.
- Bake for 20–25 minutes, then carefully lift out the baking rice using the overhanging cling film as a handle. Return the shell to the oven for a further 5–10 minutes until the base is golden and completely dry. Immediately upon removing from the oven, brush the interior of the hot pastry with a thin egg wash; this creates an essential moisture barrier that prevents the lemon custard from making the crust soggy during the final bake.
Final Custard Bake
- Pass the infused lemon custard through a fine-mesh sieve into a clean jug, using the back of a spoon to extract every drop of flavour while discarding the spent zest and any chalazae from the eggs. Carefully pour the strained liquid into your par-baked shell, filling it as close to the brim as possible for a professional, level finish.
- Briefly pass a blowtorch over the surface of the custard; the targeted heat will instantly pop any stubborn air bubbles, ensuring a glass-smooth, professional finish. Slide the tart onto the middle rack and bake at 120°C (248℉) until the custard is set at the edges but retains a slight, uniform wobble in the centre. Once baked, allow the tart to cool completely at room temperature before transferring it to the fridge to set fully, which guarantees a clean, sharp slice.
Meringue
- To create a stable, marshmallow-like topping that won't weep or collapse, we utilise the Italian method. Begin by heating sugar and a small amount of water in a saucepan until it reaches the soft-ball stage 118°C (244℉). While the syrup boils, whisk your egg whites to soft peaks in a stand mixer. Once the syrup hits the precise temperature, set the mixer to medium-high and pour the hot syrup in a slow, steady stream down the side of the bowl. Continue whisking until the meringue is thick, glossy, and the bowl feels cool to the touch.
- Pipe or spoon the cooled meringue onto the set lemon tart, ensuring you spread it right to the very edge of the pâte sucrée to "anchor" it. For the signature look, use a palette knife to create decorative swirls or a piping bag for precise peaks. Use a blowtorch to gently caramelise the surface, highlighting the texture with a deep amber toast. The high stability of the Italian meringue means it will hold its shape perfectly against the zingy, baked custard, providing a sweet, airy contrast to the sharp citrus.
Notes
1. Precision Citrus Ratios: For the perfect balance of acidity and aroma, you need exactly 100g of lemon juice and 10g of lemon zest. Weighing your juice rather than counting "number of lemons" is vital, as acidity levels vary between fruits. The 10g of zest provides the essential oils (limonene) needed for a deep, floral citrus punch that juice alone cannot achieve.
2. The "In-Oven" Fill Method: To avoid spills and ensure a perfectly level finish, place your par-baked tart shell on the oven rack before filling. Use a jug to pour the lemon custard into the shell until it reaches the absolute brim. This prevents the "slosh" factor when moving a full, liquid tart from the counter to the oven, which often leads to unsightly custard stains on the pastry rim.
3. Low & Slow Temperature Control: It is crucial to cook the custard at a low temperature (120°C). Baking eggs too quickly causes the proteins to tighten and squeeze out moisture, resulting in a "scrambled" or grainy texture. A slow bake ensures a stable, velvet-smooth set with a clean, glass-like slice.
4. The "Wobble" Indicator: Do not wait for the custard to be firm. The tart is ready when the edges are set but the centre still has a slight, uniform wobble (like jelly). The residual heat will finish the setting process as it cools; an overbaked tart will crack or become rubbery.
5. The Surface Degassing (Blowtorch Hack): After filling the tart in the oven, use a blowtorch to briefly pass over the surface of the liquid. This pops any micro-bubbles created during whisking, ensuring a perfectly smooth, mirror-like finish once baked.
6. The Moisture Barrier (Egg Wash): Never skip the egg wash seal after blind baking. By brushing the hot pastry with a thin layer of beaten egg, you create a waterproof seal that prevents the custard from soaking into the pâte sucrée, keeping your crust crisp for 24–48 hours.
7. Anchoring the Meringue: When topping the tart, ensure the Italian meringue touches the pastry edges all the way around. This "anchors" the meringue in place and prevents it from shrinking or sliding off the smooth custard surface.