1. Heat the olive oil in a large skillet over medium heat. Add the chopped onion and garlic, sautéing until the onion becomes translucent, about 5 minutes.
2. Add the sliced mushrooms to the skillet and cook until they have released their moisture and start to brown, approximately 7-8 minutes.
3. Push the mushrooms to the side of the skillet and add the ground beef. Cook until browned, breaking it up with a wooden spoon, about 8 minutes.
4. Stir in the dried thyme, Worcestershire sauce, and beef broth. Season with salt and pepper to taste.
5. Reduce the heat to low and let the mixture simmer for about 10 minutes, allowing the flavors to meld and the sauce to thicken slightly.
6. Garnish with fresh parsley before serving.

Remember, cooking is all about intuition. If the sauce seems too thick, add a bit more broth. If it’s too thin, let it simmer a little longer. Trust your senses, just as I did when learning from my mum in our little kitchen.