- Preheat oven to Gas 4, 180°C, 350°F.
- Heat the oil in large ovenproof pot. Add the joint and brown on all sides. Add the vegetables and seasoning followed by the beer and sugar. Bring to the boil, cover with lid and place in the oven for about 2 hours.
- Make dumplings: Into a bowl place the flour and suet. Add the mustard and sufficient cold water to combine together and create a very slightly sticky dough. Shape into about 6-8 small balls. After 1½-2 hours remove meat from oven and add dumplings around the edge of the meat spacing them out – for crunchy dumplings with soft centres leave the lid off. Cook for about 20 minutes until dumplings are golden.
- Remove joint from liquid and reserve, cover with foil and allow to rest for about 10 minutes before slicing.
- Remove dumplings. Skim any fat from the cooking liquid and discard. Place the remaining cooking liquid in a small pan to boil and reduce. Serve this drizzled over the sliced meat.
- Serve with dumplings and seasonal greens.