Butternut squash with spicy chilli

Name: Butternut squash with spicy chilli
Ingredients: 2 small butternut squash halved lengthways and seeds scraped out; 1 tbsp olive oil; 1 red onion chopped; 2 red chillies deseeded and finely chopped; 2 tsp ground cumin; 250g lean beef mince; 2 tbsp tomato purée; 410g can kidney bean drained and rinsed; half bunch coriander leaves chopped; 50g spinach leaves