Prepare the cauliflower by removing the leaves and washing them thoroughly. Chop the leaves as well as the thicker stems of the leaves. Wash the head of cauliflower and cut the florets into bite-sized pieces, as well as the thick stalk.
Peel and chop the sweet potato into bite-sized pieces.
To cook on the stovetop:
In a large pan on the stove, heat the oil then add the onion and fry for a few minutes until translucent. Add the garlic and fry for another minute. Add the garam masala, cumin, turmeric and chilli powder and fry for another minute.
Add remaining ingredients, bring to the boil, then reduce the heat and simmer for 15 minutes or until cooked. Check and adjust seasoning to your preferences.
Serve with rice, chapattis or naan bread.
To cook in a slow cooker:
In a frying pan on the hob, heat the oil then add the onion and fry for a few minutes until translucent. Add the garlic and fry for another minute. Add the garam masala, cumin, turmeric and chilli powder and fry for another minute.
Transfer to the slow cooker, add remaining ingredients and cook on low for 4 hours or high for 2 hours. Check and adjust seasoning to your preferences.