Season and heat oil:
Sprinkle salt and pepper onto the stew meat. In a wide pan, warm the oil over high heat.Sear beef in batches:
Place half the beef in the hot pan and sear for 2 minutes. Stir the meat and sear for another 2-3 minutes to brown other sides. Take the meat out and repeat with the rest, removing all meat from the pan.Make broth mixture:
Lower the heat to low. Pour in the beef broth, onion soup mix, 1/2 cup water, and worcestershire sauce. Stir to loosen any browned bits from the pan bottom.Simmer meat until tender:
Put the seared meat back into the pan with the broth mixture. Cover and simmer for 1.5-2 hours. Avoid a full rolling boil as it will toughen the meat. If the liquid starts to boil on the lowest heat, take off the lid and continue cooking.Thicken gravy with slurry:
In a small bowl, mix the cornstarch with the remaining 1/2 cup water until smooth. Stir this slurry into the broth, cover, and cook for another 10 minutes until the broth thickens into a gravy. Serve over white rice, mashed potatoes, or egg noodles.