Heat a little oil in a large saucepan. Add the stewing beef and fry quickly until coloured or sealed all over. Add the vegetables and mix them with the beef. Cook for 3 to 4 minutes, until all the vegetables are coloured and glazed as well as the beef. Add the flour and tomato purée and stir to coat and colour the flour.
Pour in the stock and bring to the boil, then reduce the heat to a gentle simmer and cook for 2 hours, covered, until the meat and vegetables are tender and the sauce is a nice consistency.
Meanwhile, to make the dumplings, place the flour, finely diced onion, fresh parsley and salt in a large bowl and mix together until well combined. Gently stir in some of the buttermilk, but don’t add all the buttermilk at once because the dough may not take all of the liquid.
Knead the dough very gently, just until it comes together. Roll out the dough until it’s 2cm thick, then stamp out the dumplings using a pastry cutter. Leave them to set in the fridge until required.
About 30 minutes before the stew is ready, drop in the dumplings and let them cook for 25 to 30 minutes. Spoon the stew and dumplings into warmed bowls to serve.