750g sweet potatoes (about 3 medium), scrubbed
2 tbsp sesame oil
50g cashew nuts
1 Seville orange, zest and juice
1 red chilli, finely sliced
2 lemongrass stalks, trimmed and finely sliced
20g fresh root ginger, peeled and cut into matchsticks
2 tbsp rice wine vinegar
2 tbsp fish sauce
1 tbsp palm sugar or light muscovado sugar
½ small cauliflower, trimmed and very finely sliced
2 small red chicory bulbs, bases trimmed and leaves separated
25g pack Thai basil, leaves torn or shredded
1. Preheat the oven to 200˚C, gas mark 6. Cut the sweet potatoes into 0.5cm thick slices and toss with the oil; season. Spread out on 2 large baking trays in a single layer. Roast for 30 minutes, until soft and golden. Meanwhile, toast the cashews in a small pan over a low heat for 4-5 minutes, until golden, then cool and roughly crush or chop.
2. To make the dressing, combine the Seville orange zest and juice with the chilli, lemongrass, ginger, rice wine vinegar, fish sauce and sugar. Mix well to bruise the aromatics; season. The dressing should be hot, sweet, salty and sour, so adjust the vinegar, fish sauce or sugar to taste, as needed.
3. To serve, tumble the cauliflower, chicory leaves and Thai basil together on a platter. Add the warm sweet potato slices and the dressing, finishing with the crushed cashews.