Tip the sugar into a small saucepan over a low heat along with 50ml water, stirring, until the sugar has dissolved. Set aside to cool completely. Will keep in an airtight container for up to a month.

Pour the cooled syrup into a blender along with the tequila, triple sec, Morrisons lime juice, chopped jalapeños, 1 tbsp of the jalapeño brine and five big handfuls of ice. Blend until well mixed and the ice is slushy, adding more ice if needed. Divide between 4 glasses and top with a jalapeño.