Make the posset first. Pour the cream into a large saucepan, add the sugar and cook over a low-medium heat, stirring continuously, until the sugar has dissolved, about 4 mins. Bring to a simmer and bubble for 1 min, then turn off the heat and stir in the lemon zest and juice, then the elderflower cordial. Divide between six small glasses or pots, cool to room temperature, then chill for at least 3 hrs. Will keep chilled for 24 hrs.

For the topping, if using fresh gooseberries, it’s best to trim the tops and tails using a small, sharp knife. Tip them into a saucepan with the cordial and caster sugar. Cook over a medium heat for 8-10 mins if using frozen, or 5-7 mins if fresh, or until the gooseberries are soft but retain their shape. Leave to cool to room temperature or chill in the fridge. Serve the possets topped with the cooked gooseberries.