Red lentil squash dhal

Name: Red lentil & squash dhal
Ingredients: 1 tbsp sunflower oil; 1 onion, finely chopped; 1 garlic clove, finely chopped; 1 tsp ground coriander; 1 tsp ground cumin; 1 tsp ground turmeric; ½ tsp cayenne pepper; 400g butternut squash, peeled and cut into 2cm (prepared weight); 400g can chopped tomato; 1.2l chicken stock; 1 heaped tbsp mango chutney; 300g red lentil; small pack coriander, roughly chopped; naan bread, to serve