Heat the oil in a heavy bottom pan on medium heat and cook the mustard seeds until crackling, about 2 minutes.
Add the garlic, onion and chilli and cook until onions turn golden brown, about 4 to 5 minutes. Stir in the cumin, coriander and tomato and cook until thick. Add the turnips, coconut, turmeric and salt and mix until all the ingredients are well combined.
Add 1 cup of water and cook, stirring occasionally, until the turnips are cooked, about 20-25 minutes. Increase the heat until any remaining water is absorbed. Dill can be added as a garnish.