In a large skillet, cook the beef over medium-high heat until browned and cooked through, about 5-7 minutes, making sure to crumble the beef as it cooks.
Add the mushrooms, garlic, and onion to the skillet and cook for 3-4 minutes, until the vegetables are softened.
Pour in the beef broth and heavy cream. Stir in the thyme, salt, and pepper.
Bring the mixture to a simmer and let it cook for 5-7 minutes, or until the sauce has thickened to your desired consistency.
Serve the creamy beef and mushrooms over mashed potatoes, rice, or pasta.
