- Preheat the oven to 180ºC fan oven/220ºC/gas 6.
- Heat the butter in a large hob to oven casserole and add the onions. Fry until the begin to soften.
- Add the carrots and meat and fry until the meat is no longer pink.
- Add the water, stock, pearl barley, mustard, and salt and pepper. Bring to the boil.
- Place in the oven for 1 1/2 hours. If a lot of the liquid had boiled away add more, sufficient to make a soup like consistency.
- Add the chopped parsley and serve with crusty bread.