Heat a large cast iron skillet on a medium heat. Once hot, add 2 tbsp of oil followed by the sweet potato and cauliflower. Season with salt and pepper and cook for 10 minutes stirring regularly. Add a splash of water every 3-4 minutes to stop the cauliflower and sweet potato catching.
Next, add the chopped red onions, crushed garlic and grated ginger. Stir well and allow to cook for a further 3-4 minutes.
Throw in the tomato puree, curry powder, garam masala, paprika, ground cumin, ground coriander and turmeric. Stir continuously for 1 minute.
Pour in the tomato passata, veg stock, chickpeas, green lentils, honey and season well with salt and pepper. Bring to a bubble and reduce the heat for 40-45 minutes or until the sweet potatoes have soften and the sauce has reached your desired consistency. If the sauce gets too thick before the sweet potato is cooked, then just add a splash of water as you go.
A few minutes before serving, add 1 tbsp of peanut butter and the juice of a lemon. Stir well and allow to cook for a further few minutes.
Serve the curry with the wholegrain rice along with fresh coriander and chopped nuts.