Wash the limes and dry them first.

Grate the rind to get as much lime grind as possible, but avoid grating the white pith under the green skin.

Juice all the limes and pour the juice through a fine mesh sieve to get rid of any pith, pips or large pulp.

Add about 1 inch or 2 cm of water to a medium size saucepan and bring to gentle simmer over a low to medium heat on your hob.

In a suitable bowl (stainless steel, plastic or pottery) mix the butter. sugar, lime rind and lime juice with a large pinch of salt.

Place the bowl over the saucepan and let the lemon curd mixture to dissolve. Stir gently to make sure all ingredients are incorporated and the sugar has dissolved properly (check on the back of a clean spoon for any sugar crystals).

In the meanwhile, beat the eggs together (using both yolk and egg white or 4 egg yolks if you have a leftover from another recipe).

Strain the eggs through a fine mesh sieve to get rid of any impurities.

Once everything has dissolved, add the eggs to the main mixture.

Carry on stirring the lime curd mixture, ensuring that the heat is very low and that the water doesn't boil (only simmers).

Stir gently for another 20 minutes or until the mixture thickens and becomes lovely and creamy.

To achieve a smooth lime curd, pour and press the hot mixture through a fine sieve (and discard any lime zest).

Pour carefully into prepared glasses or other suitable containers.

Keep in a refrigerator and use within 2-3 weeks.