mollymole, I can make a chicken feed my 5 kids (20, 18, 13, 11, 8) for a least 3 meals and soup.
I buy a standard free range chicken and cook it in a big pan of water with a carrot, onion, celery, salt, pepper and bay leaf. When it is cooked, I split it into 3 or 4 portions depending on what's on my menu. Usually I would make a portion from 1 breast or leg. The meat from the bottom of the carcass and wings gets set aside for soup, then the carcass goes into another pan of water with a carrot, onion, celery, seasoning etc and simmered for 24 hours to make another batch of stock.
The chicken would be turned into things like pasta bake, chicken and veg pie, chicken and veg casserole with dumplings, spicy chicken tortilla bake, risotto, curry, creamy apple juice chicken and veg, potato bake.... You only need a relatively small amount of chicken to make any of those.
The 2 lots of stock get turned into soup, a chicken, rice and veg type one and a cream of chicken or chicken noodle type one. Usually a pan of either does 2 lunches, so 4 dinners and 4 lunches for 5 from one chicken.
I can also spin out 1lb of mince to feed them 2 or 3 times like Ben10 above. Cook the mince onions and oxo cube, add tinned toms, frozen peppers, other veg. Then divide up and use as the base for meals. You could make shepherds pie, chilli and pasta bake by adding a few more basic ingredients. Or you could make tacos, spag bol and dirty rice or any number of other things.
I spend a maximum of 90pounds a week on our shopping, all in for 7 of us, so I have learned to be creative.