Jerk sweet potato & black bean curry

INGREDIENTS

• 2 onions , 1 diced, 1 roughly chopped
• 2 tbsp sunflower oil
• 50g ginger , roughly chopped
• small bunch coriander , leaves and stalks separated
• 3 tbsp jerk seasoning
• 2 thyme sprigs
• 400g can chopped tomatoes
• 4 tbsp red wine vinegar
• 3 tbsp demerara sugar
• 2 vegetable stock cubes, crumbled
• 1kg sweet potatoes , peeled and cut into chunks
• 2 x 400g cans black beans , rinsed and drained
• 450g jar roasted red peppers , cut into thick slices