Optional: If you want to use the lemons as the serving dishes, cut them in half lengthwise and use a spoon to extract the fruit, leaving just the rind in place. Be careful not to damage the structural integrity of the lemon halves. If using cups, ramekins, or other vessels, just peel the lemons or cut and juice them.
Extract and strain your lemon juice to remove seeds and most of the pulp.
In a sauce pan, stir together the heavy cream and sugar until the sugar dissolves. Bring this to a boil, and let it boil for about five minutes to reduce and thicken the cream.
2 Cups Heavy Cream, ⅔ Cup Sugar
Remove the cream from the heat and stir in the lemon juice. Set this aside and let it cool for about 15 minutes.
5 Tbsp Lemon Juice
Once cooled, pour the custard mix through your strainer again to remove any stray lumps, filling each lemon half or your custard bowls/cups as you go.
Chill your possets for at least a few hours, or overnight, so it sets. Top with whatever you like and enjoy!