1. Prepare the Lemons:

• Begin by preparing the lemon shells. Using fresh lemons, slice them lengthwise down the center. You should aim for even halves, with the rounded side of the lemon facing down.
• Use a spoon to carefully scoop out the lemon wedges from each half. Be gentle, as you want to leave the lemon peel intact, creating a small natural “bowl” for the posset custard. Save the lemon wedges for juicing—they’ll provide the fresh lemon juice needed for the posset mixture.
• Once all the wedges are removed, place the empty lemon halves on a baking sheet. Lay them cut-side up to keep the shells steady. You’ll use these lemon shells to hold the posset custard as it sets. Set them aside while you prepare the custard mixture.

2. Make the Lemon Posset Custard:

• In a medium saucepan, combine the heavy cream, granulated sugar, lemon zest, and a pinch of salt. Stir to mix everything together and place the pan over medium heat.
• As the cream heats up, the sugar will begin to dissolve into the cream, creating a smooth, velvety mixture. Stir frequently to help the sugar dissolve evenly and prevent the cream from scorching on the bottom.
• Bring the cream mixture to a light simmer. It should be hot but not boiling. Keep a close eye on it to avoid bringing the cream to a full boil, which can cause it to curdle.
• Once the mixture is simmering, remove the saucepan from the heat. Add the freshly squeezed lemon juice and stir well to combine. The acidity of the lemon juice will help the custard set and thicken.
• Allow the custard to cool down for about 15-20 minutes. During this time, a light skin will form on top of the custard, which is a sign that it’s beginning to set.

3. Strain the Mixture:

• For a perfectly smooth posset, it’s essential to strain the mixture through a fine sieve to remove any bits of lemon zest. This will leave you with a silky custard that’s perfect for filling the lemon shells. Straining also ensures that the posset has a refined texture, making it feel even more luxurious when served.

4. Fill the Lemon Shells:

• Carefully spoon or pour the strained posset mixture into each of the prepared lemon halves. Fill them to the top, but be careful not to overfill, as the custard may spill over the edges as it sets.
• Once the lemon halves are filled with the creamy posset, place them in the refrigerator to chill. Allow the possets to set for at least 3-4 hours or overnight, depending on your preference. The custard will firm up during this time, becoming silky and smooth.