Tradition calls for a hunk of beef with bone in. BSE scare says otherwise; you can't actually buy the stuff. Use lamb instead. Get shoulder, whatever amount it comes in that will fit in your largest pot (typically 1.5-2kg)
1 large onion, peeled, whole.
1tbsp salt
1tbsp freshly ground pepper (wrap peppercorns in paper, hit with hammer a few times; it's faster)
3-4 leaves bayleaf
1-2 heads of cabbage. Savoy is good. Bear in mind that's got to fit in the pot too.
5-6 large carrots, chopped
anything else you fancy from the following list: (none of these are absolutely required)
1 large potato, diced
fresh dill, chopped
fresh coriander, chopped
Put lamb in pot. Add water to cover. Add salt, pepper, onion (whole!), bayleaf. Bring to boil, skim 2-3 times (remove scum from the surface using a tablespoon). Turn heat down to low and simmer for ~3 hours (better cooked for longer than undercooked). Meanwhile, chop the cabbage (slice in half, remove stem, chop the rest into ~ 1x3cm strips).
Remove the onion and throw it out. If your pot isn't going to be large enough for the cabbage, take the meat out, peel it from the bone (it should come away very easily), throw out the bone and chuck the meat back in. Add everything that's left except any fresh herbs you might have decided to use, give it a stir and simmer for another 40-45 minutes. If you are using fresh herbs (dill, coriander etc.) add them 10-15 minutes before the end.