Infuse the cream

• Pour the cream into a saucepan with the sugar and the lemon zest.
• Warm gently over low heat, stirring until the sugar dissolves.
• Bring just to a simmer, then take off the heat.

Add the lemon juice

• Juice the lemons into a bowl.
• Whisk the lemon juice into the warm cream mixture until it thickens slightly.

Chill and set

• Pour the mixture through a sieve into a jug.
• Divide between ramekins or small glasses.
• Refrigerate until fully set.