WHAT YOU NEED

500g caster sugar
Finely grated zest of 1 lemon
12 egg yolks
240g almond meal
5g flaky sea salt
Lemon caramel*, to serve
Sour cream, whipped to soft peaks, to serve

For the almond pastry
250g unsalted butter
220g brown sugar
4g flaky sea salt
2 eggs, plus an extra egg yolk for patching
125g almond meal
320g plain fl­our
¼ tsp baking powder
Vegetable oil spray, for greasing

To make the pastry

Cream the butter, sugar, and salt in a stand mixer fitted with the paddle attachment on medium speed until pale and smooth.

Add the eggs one at a time, making sure the first egg is fully incorporated before adding the next, then reduce speed to low and add the almond meal, flour, and baking powder, beating until only just holding on to each other.

Remove from mixing bowl and gently mould the pastry into the shape of a ball with the air let out. Wrap tightly and refrigerate for an hour.

Let the pastry come to not-quite room temperature, then roll it out between two sheets of greased baking paper to a 5mm-thick round. There’s a lot of butter in this pastry, so if it gets too soft, pop it back in the fridge for a moment to help you handle it more easily.

Lightly grease a 22cm deep-sided pie or tart tin. Take the top sheet of paper of the pastry, then carefully turn the pastry over and onto the tin. Peel the remaining paper from the pastry, then gently help the pastry make its way into the bottom and sides of the tin. Trim away any overhanging pastry and patch any cracks or holes by pushing the dough back together using the pad of your index finger, wet dipped in a little extra egg yolk. (Any excess pastry can be gently smooshed back together and used one more time only; keep it wrapped in plastic in the freezer for up to 3 months.) Refrigerate the tart base for half an hour before filling.

For the filling

Make a simple sugar syrup by dissolving the caster sugar in 250ml water in a saucepan over medium heat, then allow it to cool to room temperature.

Heat oven to 150°C. Put the egg yolks into a blender and blend on low speed until they come together as one, then blend in the cooled sugar syrup until just combined.

Add the almond meal and salt, then blend again until combined. Increase speed to high and blend until almost but not fully smoothed. This last part should only take 30secs, a minute at most; you still want to feel the almonds’ presence. Pour into your tart base.

Bake the tart on the middle rack of the oven until the top is well caramelised and the filling has mostly set, save for a modest wobble in the centre, roughly 30mins.

Remove from the oven and leave to cool to room temperature before de-tinning, slicing, and serving with a pool of lemon caramel and a dollop of sour cream whipped to soft peaks, the two helping to temper the tart’s richness.

To make the lemon caramel

Ingredients
150 g (⅔ cup) caster sugar
75 ml lemon juice (from about 1½ lemons)

Method
Prepare a bowl of iced water large enough to hold a small saucepan.

Put caster sugar in a small, heavy-based saucepan, add a tablespoon of water and stir to wet the sugar. Place over medium heat and cook, without stirring, until it forms a very dark caramel.

When it starts to emit little puffs of smoke, move the pan to the water bath, chilling the base quickly to stop the cooking.

Whisking vigorously, add 45ml lemon juice to the caramel; it will protest at first, but persevere and it will calm down. Let it cool to room temperature, then add the remaining lemon juice, whisking to incorporate fully. Store at room temperature for up to a week.