Prepare the Beef: Cut the beef into bite-sized pieces and season with salt and pepper.
Sauté the Onions: In a large skillet, heat olive oil over medium heat. Add the chopped onions and sauté until translucent, about 5 minutes.
Brown the Beef: Add the beef tips to the skillet and sear on all sides until browned, about 5-7 minutes.
Add Garlic and Mushrooms: Stir in the minced garlic and sliced mushrooms, cooking for an additional 2-3 minutes.
Pour in Broth: Add the beef broth, Worcestershire sauce, thyme, and stir to combine. Bring to a simmer.
Simmer: Reduce the heat to low, cover, and let the beef simmer for 30 minutes, allowing the flavors to meld.
Thicken the Gravy: In a small bowl, mix cornstarch and water to create a slurry. Stir this into the skillet and cook for an additional 5 minutes until the gravy thickens.
Taste and Adjust: Taste the gravy and adjust seasoning if necessary, adding more salt or pepper as desired.
Serve: Remove from heat and let it sit for a few minutes before serving.