Tarte au citron: serve up a slice of sunshine

There is something inherently uplifting about a lemon. Even in literal or figurative dark times, lemons shine bright – little bumpy orbs of joy that cry out from the fruit bowl or the greengrocers to be turned into something mouth-puckering or, once paired with enough sugar, that perfect balance of sweet-sour. Perhaps I am overly sentimental, but lemons always strike me as cheering, and full of promise. Lemon curd was one of the first things I learnt to make when I began cooking, but I’ve held off turning it into a tart for a while, unable to work out how to create the exact pudding I wanted to eat.

For a long time, I have wanted to make this perfect lemon tart, but have been thwarted in my attempts. I have strong opinions on the ideal tarte au citron: I want a tart almost shocking in its lemoniness, so ridiculously zesty that it elicits inadvertent exclamations on eating. I am not here for an insipid lemon tart. But equally, I want a tart from which I can cut clean slices that wibble onto the plate, holding their shape, from the fluted pastry to the perfect, tapering nose. For a while there seemed no way of squaring the circle: to achieve the former, you have to avoid baking the filling. The flavour of the lemon is muted on baking, and muddied by the cream that tends to be folded into it. A baked lemon tart is still a lovely tart, but it’s a different one: mellow and wobbly – like a lemon-scented custard. The sharpness, the bite of the lemon, is lost. But if you simply spoon curd into the pastry shell, it’s impossible to get that beautiful clean slice: the filling will fall and flop on cutting, and it feels more like individual constituents – pastry, curd – than a cohesive pudding.