Wash the jam jars, lids and strainer in warm soapy water and rinse thoroughly. Do not dry.
Wash any silicone seals (from Kilner jars) separately with hot soapy water and set aside.
Place the clean jars, their lids (but not the silicone seals from Kilner jars) and the metal strainer into a cold oven on a baking tray and turn the oven on to 170 C/325 F/Gas 3.
Once the oven has reached temperature, the jars should be allowed to heat for about 15 to 20 minutes.
Once the jars have sterilised, turn off the oven, but leave the jars to cool in the oven, until ready to use.
Make your curd whilst the jars are being sterilised.
Make the Curd
Grate the zest from 1 lemon, 1 lime and 1 orange.
Juice all of the fruit to make up 300 ml.
Place the zest, juice, butter and sugar into a large glass bowl and place on top of a suitable-sized saucepan of simmering water.
Heat the ingredients, stirring until the butter is melted and the sugar is completely dissolved.
Remove from the heat, cool slightly and then whisk in the beaten eggs until smooth and completely incorporated.
Return the bowl to sit over the simmering water on low to medium heat and with a wooden or silicone spoon, stir continually whilst heating, until the curd is thickened enough to coat the back of the spoon (about 20 to 25 minutes).
When ready, strain the curd through the sterile tea strainer straight into the warm, sterile jars and seal immediately with the lid.
Allow to cool completely and then store in the fridge. Best consumed within 1 to 2 weeks.
* Note: nutritional information is an estimate & may vary according to portion size/ingredient variants.