Preheat the oven to 200°C/400°F/Gas mark 6.
Place the sweet potato and butternut squash in a pan, cover with boiling water and simmer for 5–6 minutes until tender. Drain well and then spread out on a baking sheet. Drizzle with half the olive oil and bake in the oven for 15 minutes until browned at the edges. Allow to cool.
Transfer the baked sweet potato and butternut squash to a large bowl and add the chickpeas, hazelnuts, watercress, tomatoes, spring onions and cucumber. Toss together and dress with the remaining olive oil and balsamic vinegar.
This recipe is extracted from Eat your Way to Lower Cholesterol, written by nutritional therapist and health writer Ian Marber and consultant cardiologist Dr Laura Corr with dietician Dr Sarah Schenker. Published by Orion, £16.99.