1.   Pour the cream into a saucepan. Add the sweetener and lemon zest, and stir to combine

2.   Place saucepan over medium-low heat. Stir while heating, bringing to a light boil. Cook until the sweetener has completely dissolved and the cream has evaporated a bit

3.   Remove the saucepan from the stovetop. Pass mixture through a fine mesh sieve to remove the lemon zest. As posset is cooling, stir frequently to prevent a skin from forming on the surface. Set aside and let rest to cool to room temperature, about 15 to 20 minutes

4.   When cooled, pour in the lemon juice, stirring well to combine. Pour into serving dishes or glasses. Cover with a tea towel or light cloth. Do not use cling wrap as it may weep, and drip over posset surface. Refrigerate for 4 to 6 hours or until the posset has set. Posset can be made ahead and kept in the refrigerator for 2 to 3 days

5.   OPTIONAL: Garnish with a light sprinkle of lemon zest and 1 tbsp of blueberries placed in the center. Alternatively, garnish with any other berries of your choice. Posset is often served with a thin wafer cookie or a shortbread cookie