Lemon curd

Wash two lemons and zest them, to about two tablespoons of zest.

Put the zest in a medium bowl (or food processor) with the sugar. Rub together by hand (or whiz in the processor) until the sugar looks wet, light yellow, like wet sand, and smells of lemon.

Roll the lemons and juice them to 100 ml, removing the seeds.

Separate six egg yolks and pass them through a sieve to remove the stringy white twizzler.

In the pot, whisk the lemon sugar into the yolks until a light pastel yellow.

Stir in the lemon juice gradually (the first splash can go through the sieve to rinse the yolk off it).

Have the cold butter ready. Over low heat, whisk for a few minutes until the curd thickens and changes color and texture; it is ready when it coats the back of a wooden spoon rather than sliding off. Test for consistency, not time or temperature.

Off the heat, add the butter in tablespoon-sized pieces and stir in; it cools and thickens the curd and gives it its texture. It loosens at first and thickens as it cools.

Transfer to a large bowl (or pie tin) to cool quickly; optionally strain to remove cooked bits of yolk and the zest.

If using within an hour or two, cover the surface with plastic so it does not form a skin; otherwise store in a closed container a week in the fridge or two months in the freezer. Chill until set.