Dice the mutton, wash and boil with salt, a dash of thyme and two slices of onion until cooked. Melt the butter in another saucepan and lightly fry the meat. Take out the meat and put in a dish. Liightly fry the onion in the same hot oil, add the rest of the ingredients. Add the mutton stock and extra water if necessary. Allow to simmer for 30 minutes. Add the fried mutton and simmer another 10 minutes.