1. Preheat a heavy, deep pan over medium-high heat with olive oil. Add the ground beef and stir continuously to break it down into small pieces. Then add the diced onions and minced garlic. Sauté until the onion is translucent and golden brown, which builds the base flavor.

2. Add the sliced mushrooms to the pan and sauté for about 5 minutes, or until the mushrooms soften. If the mushrooms release a lot of liquid, allow it to evaporate by cooking a bit longer to concentrate the flavors.

3. Sprinkle the flour over the mixture and stir constantly to fully incorporate it. This step helps thicken the sauce. Scrape the bottom of the pan to mix in any flour lumps for a smooth consistency.

4. Pour in the beef broth and heavy whipping cream, then add Worcestershire sauce, salt, and black pepper. Stir well and bring the mixture to a simmer over medium heat. Once simmering, reduce the heat to low and let it cook gently for about 5 minutes to allow the flavors to meld and the sauce to thicken.

5. Remove the pan from heat and stir in the sour cream thoroughly, creating a rich and creamy sauce. Adjust seasoning if necessary. Serve hot over your choice of noodles, rice, or potatoes for a hearty meal.