Peel the sweet potatoes and dice them into small cubes. Cut the cauliflower (throw away most of the large stem) so that you have small flowers all roughly the same size, as this effects the required cooking time. Wash and drain in a colander.
Heat the coconut oil in a wide and deep pot . Add the mustard seeds and wait until they start popping. Add, cumin and cloves.
Stir for a while and add onions. When the onion start to turn brown add the rest of the spices (except for turmeric).
Put the cauliflower in the pot and fry in the oil and spices (keep stirring to prevent spices sticking to the pot and burning. (if the mixture does start to stick to the bottom add a couple of tablespoons of water). After about five minutes add the sweet potatoes the and turmeric into the pot continue to cook.
Continue stirring the vegetables under medium heat for another two minutes and add ½ cup of water and reduce heat to low. Cover pot and let cook until the vegetables are cooked. Check tenderness of vegetables (I prefer them to be 'al dente') once they are, turn up the heat and dry off the water stirring the pot to ensure that the masala mixture does not stick to the bottom of the pan and burn.
Put into a serving dish, sprinkle some fresh coriander leaves on top and serve.