Prep the lemons. Wash and dry the lemons. Finely zest one lemon, avoiding the bitter white pith. Juice enough lemons to get 1/3 cup (80 ml) of juice. Strain the juice to remove seeds and pulp.

Warm the cream and sugar. In a medium saucepan, add 2 cups (480 ml) heavy cream and 1/2 cup (100 g) sugar. Set over medium heat. Stir gently as it warms to dissolve the sugar and prevent scorching.

Bring to a gentle boil. Once the sugar is dissolved, bring the mixture to a steady boil and let it bubble for 2–3 minutes. Keep it at a controlled simmer-boil, not a raging boil. This slightly reduces and thickens the cream.

Remove from heat and add lemon. Take the pan off the heat. Stir in the lemon zest and 1/3 cup (80 ml) lemon juice. Whisk for 30 seconds. You’ll notice the cream thickening as the acid reacts with the dairy.

Rest briefly. Let the mixture sit for 5 minutes to allow any foam to settle. Skim off excess foam if you want an ultra-smooth finish.

Pour into serving dishes. Divide the mixture among 4–6 small ramekins, glasses, or cups. Tap each gently on the counter to release air bubbles.

Chill to set. Cover and refrigerate for at least 3 hours, preferably 4–6. The posset will thicken into a soft, creamy set.

Garnish and serve. Serve chilled. Top with a few fresh berries, a twist of lemon zest, or a small shortbread cookie on the side.