01 - Heat 1 tablespoon of olive oil and 1 tablespoon of butter in a large skillet over medium-high heat.
02 - Add beef pieces in a single layer, season with salt and pepper, and sear for 2 to 3 minutes per side until browned. Work in batches if needed to avoid crowding the pan. Set browned beef aside on a plate.
03 - Lower heat to medium. Add the remaining olive oil and butter. Sauté onions and mushrooms if using for 2 to 3 minutes until softened. Stir in garlic and cook for 1 minute until fragrant.
04 - Sprinkle flour over the vegetable mixture, stirring well for about 1 minute to cook off the raw flour taste.
05 - Slowly pour in beef broth while stirring and scraping up any browned bits from the bottom of the pan. Stir in Worcestershire sauce and dried thyme.
06 - Bring to a gentle simmer. Return the steak tips and any accumulated juices to the skillet. Cook uncovered, stirring occasionally, for 8 to 10 minutes until the beef is tender and the gravy thickens to your liking.
07 - Taste the gravy and adjust salt and pepper as needed.
08 - Sprinkle with fresh parsley and serve hot over rice, mashed potatoes, or egg noodles.