Preheat the oven to 160 degrees C, top / bottom heat.
Heat the oil in a large saucepan or roasting pan over medium heat. Sear the meat on all sides, remove from the pot / roaster. Place the onions in the roaster and sweat until golden brown. Salt and pepper the meat and place back in the roaster.
Combine the beef stock, ketchup and Worcestershire sauce in a bowl, pour over the meat. Add tomatoes. Bring the liquid to a boil, then remove the roaster from the stove, put the lid on and place in the oven.
Leave in the oven for 3 hours, in the last 30 minutes of the roasting time, peel the potatoes and cut them into large pieces, as well as clean the carrots and cut into pieces approx. 2 cm in size. Take the roasting pan out of the oven after 3 hours, add the potatoes and carrots and place the roasting pan in the oven for another 30 minutes.
Take the roasting pan out of the oven and stir in the lemon juice. Garnish with parsley.
Variant:
Instead of 500 ml beef stock take 250 ml red wine and 250 ml beef stock and also add 1 bay leaf and 2 thyme stalks.