In a small pan, mix the sugar, tequila, triple sec and bitters with 375ml water. Add the chilli and stir over a medium heat for a few minutes to dissolve the sugar. Remove from the heat, add the lime juice and leave to cool. (Or put the pan in a bowl of iced water and stir regularly until cool.)

Discard the chilli, then divide the mixture among the lolly moulds. Push a slice of lime into each, add the sticks (see Before you start), cover and freeze for at least 6 hours, ideally overnight, until solid.

Remove from the freezer 10 minutes before eating. Dunk the moulds into a bowl of warm water if needed to help release the lollies. If using, spread some Tajín on a plate, then press the lollies into it to add a zingy crust.