Marinate the beef cubes in 30 ml Worcestershire sauce and 30 ml olive oil in zip-lock bags or a bowl for 1 hour, ensuring the beef is completely covered in the marinade.
While the beef is marinating, in a flat-bottomed wok, skillet or frying pan over medium-high heat fry the lightly pounded garlic cloves in two tablespoons of olive oil until golden and fragrant, then transfer to your Dutch oven or heavy stew pot with lid that will fit into your oven, then fry the bacon in the same oil and transfer to the Dutch oven/stew pot.
Top up the oil with another two tablespoons of olive oil, turn the heat to high, then fry the vegetables for a few minutes until blistered, one ingredient at a time, seasoning each with a pinch of sea salt and some freshly ground cracked black pepper, then transfer to the Dutch oven or stew pot.
Tip the beef cubes and marinade into the same pan and sear over high heat until brown, then transfer to the pot, along with any remaining marinade.
Add the Guinness, beef stock, Worcestershire sauce, spices and herbs to the pot, stir to combine everything, and simmer on low heat, covered, for an hour or two until the beef is tender. The longer you can leave the stew to simmer the better; stir occasionally to ensure it’s not sticking.
When the beef is tender, with a large ladle transfer 3-4 scoops of the stew liquid to a small pot and over high heat bring to a boil, then reduce to a simmer.
In a small frying pan over medium heat, make the roux by melting the butter, then adding the flour, one tablespoon at a time, stirring until the flour is fully dissolved, and continuing to stir for a couple of minutes.
Gradually transfer the roux to the small pot of boiled stew juices, whisking to combine well to create a thick full-flavoured gravy. Add this to the Dutch oven/stew pot and stir to completely incorporate. Taste the stew, adjust the seasoning to your palate, then leave to simmer on low while you make the dumplings.
Preheat the oven to 180°C/350°F, then make the dumplings: to a large mixing bowl add the self raising flour, grated cheddar cheese, butter, salt, and parsley, and, using your fingertips or a spoon, combine the ingredients, rubbing the butter into the flour to meld together as best as you can.
Gradually add the milk, incorporating it well enough to create something almost resembling dough – don’t worry if it’s not smooth, the dumplings are meant to be rustic-looking – then tip it out onto a floured surface, knead just enough to be able to roll it into a log shape, divide it into 12 pieces, then roll each piece between two hands to shape it into a ball.
Return to your stew, turn the heat off, and use a fork and tablespoon to pull the beef pieces apart a little, then stir them through the gravy. Arrange the dumplings on top of the stew, ensuring there’s space between each dumpling as they will rise a little.
Put the lid on the Dutch oven/stew pot and slide it into the oven to cook for 30 minutes. Remove the lid and if needed move to a higher shelf to cook for another 15 minutes or so until the dumplings are golden and have crispy tops.
Plate and garnish with finely-chopped fresh flat leaf parsley and serve immediately.