Step 1

Start off by adding you blackberries to a medium saucepan together with your lemon juice and sugar.

Step 2

Place this over a medium high heat and cook, stirring occasionally until the sugar has dissolved and the berries have broken down. Continue cooking until the mixture boils.

Step 3

Once boiled, remove the pan from the heat and strain the mixture through a sieve to remove the pulp. Return the liquid to the saucepan, but keep off the heat.

Step 4

In a small bowl whisk together the eggs, then slowly add these to the saucepan (while off the heat), whisking the juices continuously.

Step 5

Return the saucepan to a medium high heat, whisking regularly while it thickens. This normally takes about 15 minutes until the curd coats the back of a spoon.

Step 6

Remove from the heat and add the butter, whisking through to melt.

Step 7

Pour the curd into a heatproof bowl, jar or other container to cool completely. This will continue to thicken a bit as it cools, so you should expect it to still be pourable at this stage rather than spreadable.