Spicy squash salad

Name: Spicy squash salad
Ingredients: 2.4kg/5lb 3oz butternut squash or pumpkin, peeled, seeds removed, chopped into 2cm/1in cubes; 2-3 large red chillies, seeds removed, sliced; 1½ tsp ground cumin; 1½ tsp dried chilli flakes; 80ml/3fl oz good olive oil; 150g/5½oz pak choi leaves, roughly chopped; 150g/5½oz baby spinach leaves; large handful pitted black olives; 300g/10oz goats’ cheese, crumbled (optional); salt and freshly ground black pepper; 3 tbsp red wine vinegar; 130ml/4fl oz olive oil; 5 spring onions, trimmed and chopped at an angle