Heat olive oil in a large skillet over medium heat.
Add diced onions and minced garlic; sauté until translucent.
Season beef tips with salt and pepper, then add to the skillet.
Brown the beef tips on all sides for about 5 minutes.
Stir in sliced mushrooms and cook until soft.
Sprinkle flour over the beef and veggies, stirring to coat.
Gradually add beef broth, whisking to avoid lumps.
Stir in Worcestershire sauce and thyme; bring to a simmer.
Reduce heat and let it simmer for 15-20 minutes until thickened.
Serve hot over mashed potatoes or rice.