Place the beef in a large non-reactive bowl. Add the marinade ingredients, peeling and finely slicing the garlic first, then cover and refrigerate for at least 6 hours, or preferably overnight.
Peel the baby onions. If using fresh, peel and roughly chop the tomatoes.
Heat the oil over medium heat in a large saucepan and sauté the onions for 5 minutes or until softened. Remove with a slotted spoon and set aside.
Sauté the beef, reserving the marinade, for about 8 to 10 minutes, or until browned on all sides.
Return the onions to the saucepan, add the marinade, tomatoes and tomato purée and enough water to just cover the stew. Season generously with sea salt and freshly ground black pepper.
Bring to the boil then simmer for 1½ to 2 hours, or until the beef is tender and the sauce has thickened.
Serve with pasta and grated hard cheese, such as kefalotiri, pecorino or Parmesan.