Combine the heavy cream, white sugar, and lemon zest in a medium saucepan and bring to a boil over medium-high heat.
Continue boiling, stirring constantly, for 8-12 minutes, or until the amount has reduced down to exactly 2 cups. Side Note: Turn the heat down a bit if the mixture tries to boil over the pan. Watch it carefully!
Remove the mixture from the heat and stir in the fresh lemon juice.
Set aside to cool until a skin forms on top, about 20 minutes.
Strain the mixture through a fine sieve then divide the mixture into 4-6 small glasses, ramekins, or small jars.
Refrigerate uncovered for 3 hours until set. You can place plastic wrap over the glasses after three hours until ready to serve.
Serve with fresh berries on top and enjoy.