Turkish-style stuffed aubergine with saffron and yoghurt dip

1 aubergine, halved lengthways

1 red onion, roughly chopped

1 red pepper, deseeded and roughly chopped

1 courgette, roughly chopped

1tsp harissa paste

1tbsp olive oil

Olive oil spray, to cook

2tbsp pomegranate seeds, to garnish

A small bunch of fresh coriander leaves, picked and chopped, to garnish

Sea salt and freshly ground black pepper

For the saffron and yoghurt sauce:

A pinch of saffron (optional)

120ml low-fat Greek yoghurt