50gvegan butterstick butter, not margarine, *see notes
Zest and juice the lemons.
Add the soy milk, sugar, and cornstarch to a saucepan and whisk until smooth without any lumps. Add the lemon juice and lemon zest and whisk again to combine.
Place the saucepan on medium-high heat and bring to a simmer. Turn down the heat slightly to a gentle simmer. Cook for 12-15 minutes, while stirring alternating with a rubber spatula and a whisk to prevent the mixture from sticking to the pan. The mixture will thicken and should coat the back of the spatula.
Remove the saucepan from the heat and stir in the vegan butter until completely incorporated and you have a smooth curd. Allow it to cool to room temperature for 20 minutes.
How to store and serve
Transfer the lemon curd to an airtight jar and refrigerate until ready to use. The curd will thicken in the fridge, so you can gently heat and melt it in a saucepan anytime you need a runnier curd consistency.
Granulated sugar: Some white sugar is not vegan, if in doubt use organic sugar.
Lemon juice: Use freshly squeezed, not bottled juice.
Cornstarch: Swap for arrowroot starch.
Vegan butter: You can swap this for coconut cream or thick full-fat canned coconut milk. Just note that the consistency may not be quite as set as with butter.
Soy milk: Swap for another unsweetened non-dairy milk of your choice. Almond milk and oat milk both work well.