Place the pineapple chunks in the food processor and whiz until you have mostly juice. Strain the pineapple juice through a fine sieve. This makes around 2 cups (500 ml) of juice. You can use store-bought pineapple juice if you like, but fresh pineapple is pretty spectacular.

In a heatproof bowl, pour a little boiling water over the mint sprigs. Remove the sprigs and run immediately under ice-cold water. Chop the mint finely and stir it into the strained pineapple juice. Taste and add agave or sugar if you think you should.

Freeze in a shallow metal container for around 2 hours. Check on it and use a fork to break up what should be shards of icy pineapple mixture. Once you’ve broken it up, refreeze again for a few hours. Using a fork, scrape the granita into glasses and serve.