Tarte au Citron

To get that quakingly wobbly set of lemon custard that makes this the tart of tarts, the temperature of the oven has to be much lower for the second part of the cooking, and then you have to watch it like a hawk. Gently nudging the tin is the best way, and if only the very centre quakes, remove the tart, it will carry on cooking on the rack, hold your nerve.

Please make sure you taste the raw mixture, lemons come in all sizes, so you may need to add juice to get that lip-s