Place sweet potato in a medium saucepan with enough water to cover them. Add the stock powder or use liquid stock instead of water. Bring to boil and cook for 10-15 minutes until soft when poked with a fork.

Heat a large frying pan with a dollop of ghee and sauté the onions for 3-4 minutes. Add kale and cabbage and another dollop of ghee. Season with a 1/2 teaspoon of sea salt and cook over medium heat for about 5 minutes, stirring occasionally. The cabbage and kale will start to wilt and decrease in size. Add garlic, lemon zest and a few tablespoons of water and cook for a further 4-5 minutes. Set aside.

Finally, strain the potatoes and place them in a food processor or use a potato masher to mash them into a smooth puree. Season with a good pinch of nutmeg, black pepper and add the butter. Process until well incorporated and smooth and transfer to the frying pan with the the cabbage. Stir together and taste for salt. Serve with a little extra lemon zest and back pepper on top. Enjoy!