Begin by peeling and finely chopping the onions. Heat the olive oil in a large pan over a fairly high heat, then add the onions and sauté for about 3 to 4 minutes until they start to soften and turn translucent. Next, crush the garlic clove and add it alongside the minced beef to the pan. Fry the mixture together, stirring regularly, until the mince browns nicely and the garlic is fragrant. This step is crucial as browning develops the rich flavors at the base of your sauce. Add the sliced mushrooms along with the dried oregano to the pan. Continue to cook for an additional two minutes, allowing the mushrooms to release their moisture and meld with the seasonings. Now, stir in the canned tomatoes, hot beef stock, tomato puree, Worcestershire sauce, and season well with salt and pepper. Bring the mixture to a rolling boil before reducing the heat to low. Cover the pan and let the sauce gently simmer for 30 minutes, stirring occasionally to prevent sticking and ensure even cooking. While the sauce simmers, bring a large pot of salted water to a boil. Add the spaghetti and cook according to the packet instructions until al dente. Once cooked, drain the pasta well, then run hot water over it briefly to keep it warm and prevent sticking. Return the spaghetti to the pan and, if desired, toss with a dash of olive oil to enhance glossiness and flavor. Pour the rich meat sauce over the pasta and gently mix to combine fully. Serve your delicious Spaghetti Bolognese steaming hot in bowls. Don't forget to pass around some freshly grated Parmesan cheese — sprinkling it on top adds that perfect savory finish to this classic Italian meal. Tips: For a deeper flavor, you can simmer the sauce for up to an hour if time allows. Adding a splash of red wine when adding the tomatoes also enriches the sauce. For texture, consider mixing some grated carrot into the mince at the start for subtle sweetness.