Prepare the jars and lids

Wash 3 small jars with plastic-lined lids in hot soapy water then rinse and drain them.

Sterilize the jars and lids by putting on a baking tray in the oven at its lowest setting.

Turn off the oven when the jars and lids are hot but leave them inside until you're ready to pot Orange Curd. If they cool before the curd is ready, switch the oven on again: the curd and the jars must be hot when potting up.

Remove the zest from the orange and chop it finely.

Squeeze the juice from the oranges and the lemon half: you will need approximately 175 ml in total.

Lightly beat the eggs until just combined.

Melt the butter in a saucepan over medium heat.

Add the sugar and the orange zest, plus the citrus juices strained through a sieve. Stir until the sugar is completely dissolved.

Turn the heat down to low. Tip: if you have a food thermometer, check that the mixture is not higher than 50℃ before adding the eggs.

Strain the beaten eggs through a sieve and into the saucepan then gently stir in with a whisk.

Switch to a spoon and cook the mixture without boiling it, stirring occasionally, until it is thick and coats the back of the spoon. This should take 10 - 30 minutes.

Alternative methods

1. Double Boiler. To make overheating less likely, make the curd in a heatproof bowl over a saucepan of simmering water. Don't let the water touch the bowl.

2. Microwave. Put the butter, sugar, zest and juices in a microwave safe bowl and heat to melt the butter and dissolve the sugar, regularly stirring. Gently whisk in the eggs then heat in 30 - 40 second bursts, stirring between each burst. Do not overheat and when the curd is nearly ready, reduce to 10 - 15 second bursts.

IMPORTANT: for ALL methods do overheat the mixture. If you have a food thermometer, check that it is is no higher than 50℃ before adding the eggs and don't let it get higher than 84℃ after adding them.

When the curd is ready, immediately pour into the hot sterilized jars. Protecting your hands with a cloth, screw on the lids and leave to cool. When the jars are cooler, it should be possible to tighten the lids a little more.

Once cold, the jars can be labelled and stored in a cool, dark place or the fridge.

If the jars have an airtight seal (i.e. when completely cold the lids don't spring back with a popping sound when you press down on the middle) the curd should keep for 4 weeks in a cool, dark, dry place, longer if in the fridge. Once open store in the fridge and use within 1 - 2 weeks.

If you don't have an airtight seal, keep in the fridge and use within 1 - 2 weeks.

Curd too runny when completely cold?

This means the curd wasn't cooked enough. Remove it from the jars and cook further using any of the methods above. Be sure to wash and sterilize the jars again before refilling.