Lemon curd

Whisk lemon juice and zest with sugar and eggs in a heatproof bowl, then set it over gently simmering water. Stir constantly for about 8–12 minutes, until it thickly coats the back of a spoon; keep the bowl above the water, not touching it.

Dip in a spoon and draw a line through the coating with your finger: it should stay clear. The curd thickens further as it cools, so take it off the heat once it coats the spoon rather than waiting for it to look fully firm.

Spoon it into a clean, airtight container, cool promptly and refrigerate; use within about a week. It also freezes well for up to a few months—thaw it overnight in the fridge and whisk briefly to smooth it.

Spread it on toast, scones or crumpets, or spoon it into yoghurt, pancakes and porridge. It is also used to fill lemon tarts, cakes, meringue pies and sandwich biscuits.

Usually, yes: both make a lemon filling, but lemon curd is egg-thickened and often sharper, while lemon cream tends to be richer and softer. Use curd as a ready-made filling, and avoid baking it for a long time, which can make it split.

No. Lemon curd is a sweet, tangy spread made with lemon, eggs, sugar and butter; lemon butter is essentially butter flavoured with lemon and is much fattier. They are not interchangeable in a recipe without changing its sweetness and texture.

Yes. Replace the butter with a neutral oil or leave it out for a less rich curd; the eggs still thicken it, though the result will be less silky. Stir in any replacement fat after taking the curd off the heat.

Despite the name, it is not made by curdling milk and contains no curds. The word refers to its thick, set consistency; lemon juice, eggs and gentle heat create the texture.