1. In a pot, add the cornstarch, sugar, lemon juice and mix well until completely integrated.
2. Add the lemon zest to the preparation, plant-based milk, and margarine.
3. Cook the mixture over medium heat for a couple of minutes, stirring constantly.
4. Cook and mix until you get a creamy consistency.
5. Remove from heat, let cool at room temperature.
6. Remove from heat, let cool at room temperature.