Slow Cooked Lamb Shanks

I think my Dad invented this, or Mum or adapted it, or I adapted it. Can't remember but it comes from my family anyway.

1 onion
1 potato per person
2 carrots
1 lamb shank per person and one over
tub tomato paste
2 cups chicken stock
tomato sauce maybe 2 tablespoons
1 tablespoon chilli sauce
4 tablespoons flour

Chop veges and place in a greased casserole dish with the lamb shanks. (Trim off excess fat first). Mix the rest of the ingredients together in a jug, pour over lamb and veges. Bake at 150C for 3 and a half hours. Alternately about 8 hours in a slow cooker on low would do it too, though I haven't tested it. Serve with mash and broccoli or a green of your choice