Combine lemon juice, lemon zest, vegan margarine, and sugar in the top of a double boiler.

Stir the mixture continuously over simmering water for approximately 20 minutes, ensuring the sugar dissolves completely and the curd thickens.

In a separate bowl, hydrate the vegan gelatin with a small amount of the hot curd mixture.

Stir until the gelatin is fully dissolved.

Pour the gelatin mixture back into the remaining curd in the double boiler.

Continue stirring until the curd reaches the desired thickness.

Transfer the vegan lemon curd to sterilized jars or containers.

Refrigerate until chilled and set.