Brown the bones and the shin of beef in a roasting tin in a preheated oven, 200°C/400°F (gas mark 6), for about 30 minutes. Transfer to a large pan and cover with the water. Add the vegetables to the roasting pan and roast them for about 10 minutes, until browned. Tip them into the pan with the bones, add the salt and bouquet garni, then bring to the boil. Reduce the heat, cover and simmer for about 3–4 hours, skimming off any fat or scum from the surface from time to time.
Cool slightly, then strain through a fine sieve. Cool completely and refrigerate. Use within 2 days or freeze and use within 3 months.