Heat up the olive oil in a heavy-based saucepan that you have a good lid for, and brown the pork generously on all sides. Season generously, add the sage and balsamic vinegar, put the lid on and leave it on a very low heat for about 90 minutes. And I mean a low heat. Occasionally check you have enough liquid in the saucepan and if you think it’s getting a little dry, add in some water. After this amount of time, add the 200mls of water, and the rest of the ingredients and put back on to cook for at least another 90 minutes. But do check occasionally that it’s not burning. Again, if it gets too dry, add some more water and baste the pork. You can turn it over occasionally, too. All in all, aim for at least three hours gentle cooking. Then let it cool down in the pan and when it is cool enough to handle, slice, drizzle with the cooking liquor and stuff into buttered baguettes, filled with some crunchy baby gem lettuce. Say “bon” and “alors” a lot and if you feel like being really decadent, serve with a rich, garlicky aioli which is really just some good mayo with plenty of crushed garlic added.