Turkish stuffed aubergines

Ingredients

• 4 tbsp olive oil
• 3 onions, finely chopped
• 5 garlic cloves, finely chopped
• 2 tsp ground cumin
• ½ tsp crushed chilli flakes
• 8 large tomatoes, quartered
• 2 tsp tomato purée
• 1 tsp sugar
• 4 aubergines, halved lengthways, flesh scooped out and chopped
• 1 x 28g pack flat-leaf parsley, leaves only
• 40g pine nuts, toasted
• 1 x 28g pack mint, leaves only, chopped
• juice of ½ lemon