I covered the carcass, leftover potatoes, rosemary, onions, peas and mint sauce with cold water and brought it to the boil. I let this simmer for a couple of hours and then left to cool. While it was simmering, I soaked some green lentils. When it was back to room temperature, I took the carcass out and pulled all the meaty bits off, putting them back in the pan, and discarding the bones. I added the lentils and cooked the soup once again, until they softened, seasoned it, and ate it for supper with some fresh crusty bread
I ate this for dinner the next day in exactly the same way, adding just a bit more water when cooking. The final day, however, I added a bowl of water to make it the right consistency for a soup, and also a handful of quinoa and some spicy pepper sauce, and created another soup altogether. I can't wait to try making this soup with other leftover roast meats and vegetables, as I have a feeling it will taste completely different every time - a great discovery!