Prepare the mint infusion by pouring 1 cup (240 ml) of boiling water on 3 large sprigs of mint; set aside to steep and cool for at least 30 minutes. Meanwhile, boil the 3 cups of water and dissolve the sugar in it. Cool, then add the mint, lemon juice and mint infusion. Cool again, and pour the mixture into a hand-cranked ice-cream freezer, if you have one, or into a metal tray in the freezer. If you use a hand-cranked machine, pack it with ice and keep turning! Excellent for bicep development – or get the children to do it. If you put it in a metal tray in the ordinary freezer, make sure to remove it when it is partially frozen and beat it vigorously before refreezing. Repeat the process at least once before allowing it to harden fully.
We found a glorious hand-cranked ice-cream freezer in a junk shop and had great fun using it, but for busy people the electric ice-cream makers that do all the work are undoubtedly much more convenient.