Butternut squash and sweet potato curry

Name: Butternut squash and sweet potato curry
Ingredients: 1 red onion, cut into chunks; 2–3 red chillies, stalks removed and cut into three; 50g/1¾oz fresh ginger, peeled and cut into thick coins; 2 garlic cloves, halved; 15g/½oz fresh turmeric, peeled and roughly chopped (or 1 tsp ground turmeric); 1 tsp ground coriander; ½ tsp ground cinnamon; 1 tsp sea salt flakes, or to taste; 2 tbsp coconut oil or vegetable oil; 1 x 400ml tin coconut milk; 350ml/12fl oz vegetable stock; 400g tin chopped tomatoes; 500g/1lb 2oz sweet potatoes, peeled and cut into large bite-sized pieces; 1 large butternut squash, peeled, de-seeded and cut into bite-sized pieces; 300g/10½oz black Venus rice, to serve; handful coriander, roughly chopped; 2 limes, cut into wedges