I don't really have a recipe - I just throw things in in a random fashion. I'll have a go...
Chicken carcass - bung in big pan, cover with cold water, throw in a couple of bay leaves, a few peppercorns, salt, and a couple of stockcubes organic chicken bouillon. Bring to boil, then simmer gently for..er..quite a long time.
Get very large mixing bowl and pour contents through a sieve - discard bay leaves, peppercorns etc. Leave carcass to cool a bit then pick all the meat off and put it in the fridge. Leave stock to cool then skim any fat/scum off the top.
Chop up vegetables - I use whatever I happen to have but that will probably include leeks, onions, carrots, potatoes, celery. You can saute them in a bit of butter first or just cook them in the stock. I generally don't put potatoes in straight away as they can get too soft - start with the herd stuff! I'll also put in sweet potatoes sometimes, swede, turnip, parsnip...really any old thing. When the vegetables are tender I put the chicken back in and any quick-cooking vegetables (cauliflower, broccoli, courgettes, shredded cabbage). If you have any veg left over from Sunday lunch bung them in at this stage too - any earlier and they will just turn to mush. I usually chuck in a can of sweetcorn too as we all like it in soup. Check the taste - you may need more salt and pepper.
You can add a splash of single cream if you like, just before serving.