1

Preheat the oven to 200c, 180c fan, gas mark 6. Place the rhubarb on a baking tray with half of the agave and ginger. Cover with foil and roast for 15 minutes, remove from the oven and let cool.

2

Blitz the rhubarb, bananas and remaining agave in a blender. Increase the speed and add the buttermilk. Pour the mixture into a container and freeze overnight.

3

To make the brittle, mist a nonstick baking tray with cooking spray. Melt the butter with the caster sugar and 1 tsp water in a small pan set over a low heat. Stir in the agave syrup and bring to a boil. Bubble for 8 minutes until it turns amber, then pour onto the baking tray. Scatter over the nuts and salt. Set aside, for 10-15 minutes to harden, then break into shards.

4

Remove the sorbet from the freezer and set aside for 15-20 minutes to thaw slightly. Blitz in the blender until there are no large ice crystals. Scoop the sorbet into 16 balls and serve 2 per person with the brittle.