Put the lamb, chicken stock, onion and bouquet garni into a large saucepan. Bring to a simmer, cover partially with a lid and cook for 1¼ hours, skimming from time to time.
Add the potatoes and carrots to the pot and continue to simmer for 20 minutes. Add the cabbage and simmer for 10 minutes. Remove the bouquet garni, season with salt and pepper and scatter over th