Adaptrix
Lime
Lime matches lemon in acidity,
so swap the juice amounts gram
for gram. Add a final fresh zing of
freshly grated lime zest over the
baked tart.

Meyer lemon
Add the fine zest of two Meyer
lemons to the filling. Reduce the
sugar by 30 g (1 oz) to account
for the subtle sourness.

Remove from the oven and allow to cool at room temperature for at
least 1 hour (longer for deeper tarts) before cutting the first slice. You
can also chill to hasten the setting (and eating).

Cracks along the crustline will appear if overcooked or over time, if you keep
the tart for a few days. To repair, a little smear across the crack towards the
crust with a small palette knife will cover it up.

Tart-eating temperature: Cool to room temperature for 1 hour, then
chill for 30 minutes (unchilled is a little too tremulous). Or chill further
for creamier, stable slices.

Dust with icing sugar and brûlée (see Burn it, page 93) or leave it
pure sunshiny yellow.

* Overcooked? Slightly browned overcooked lemon tarts can be salvaged! Get
the tart into the fridge as soon and as carefully as possible. When it is chilled
to just cold, spread the top with billowy whipped cream and a fresh grating
of lemon zest. Hello, lemon cream pie! Or follow the brûlée steps (see Burn it,
page 93). The filling will be a little cottage cheesy curd-like at the side, but the
centre should still be silky smooth and lemon delicious.