Cook over low heat until it starts to thicken, stirring constantly with a wooden spoon. This should take about 10 minutes. It's ready when reduced by about half, and the curd coats the back of a wooden spoon.
Add the vegan butter to the hot curd and whisk to melt and incorporate fully.
60 grams vegan butter, cut into small pieces
Pour your lemon curd into a glass jar and loosely cover with a lid to cool at room temperature. Once cooled, seal tightly and refrigerate.
After refrigerating, the curd should be set and pudding-like in texture. It will keep up to a couple weeks in the refrigerator.