Cook the pears. Chop the pears and put them in a small pan with the water, sugar, cardamom pods and lemon peel. Cover and cook over low heat for 12–15 minutes, until completely soft.

Blend. Fish out the cardamom pods and lemon peel. Blend the pears with the vanilla and lemon juice until completely smooth; the lemon keeps the purée pale rather than brown.

Chill. Pass the purée through a sieve for a silky texture and chill until cold, at least 2 hours. Warm purée will kill the bubbles on contact.

Build. Spoon 2 tablespoons of cold purée into each chilled flute.

Top. Pour the prosecco slowly down the inside of the glass, letting the foam settle before topping up. Stir once with a bar spoon, just enough to marble the purée through.

Finish. Slap a thyme sprig against your palm to wake up the oils, drop it in, and add a thin slice of pear to the rim.