Boil the blood orange juice with sugar.
Mix the egg and yolks in a bowl.
Slowly pour the hot blood orange juice to the eggs while stirring.
Pour the whole mixture back into a saucepan and stir over medium heat until it thickens. (May take a few minutes).
Add the butter in pieces, and stir.
Pour into clean jars while still hot.
The blood orange curd will keep in the fridge for about 2 weeks.