Trim any excess fat from the meat and cut into bite-sized pieces.
Combine the flour and seasoning in a medium bowl. Add the meat and toss to generously coat.
Add a thin layer of oil in a large cast iron skillet over medium-high heat. Add the meat and brown on the sides for about 2 to 3 minutes. Note: you don’t need the meat cooked through, just the outside browned. Remove the meat from the skillet and keep warm.
Return to the skillet, turn the heat down to medium and melt the butter. Stir in the onion. Cook until the onion begins to get tender, stirring occasionally, then stir in the mushrooms and garlic. Continue cooking for about 2 to 3 minutes. Pour the contents of the skillet into a pot.
Return the meat to the skillet and reduce the heat to low. Add the wine and let it reduce by half, stirring frequently. Pour into the pot.
To the pot, add the beef broth, Worcestershire sauce, bouillon cube and thyme. Bring to a boil. Reduce the heat to a simmer for 1 to 1 ½ hours, or until the meat is tender. Serve warm over rice or mashed potatoes, if desired.
Note: If you would like the sauce/gravy thicker, dilute 3 tablespoons of cornstarch in ¼ cup of cold water. Stir the mixture into the beef tips and cook until it thickens to desired consistency.
For a slow cooker: Flour and brown the meat as directed above. Add all the ingredients to a slow cooker on low for about 6 - 7 hours or high for 4 - 5 hours, or until the meat is tender.