Heat oil in a large heavy skillet over medium-high heat. Brown steaks for 3 to 5 minutes on each side. While browning, season both sides with onion powder, garlic powder, salt and pepper. Transfer steaks to a 9x13 inch casserole dish, and sprinkle with chopped onion and sliced mushrooms.
In a small bowl, combine condensed mushroom soup, water, onion soup mix and Worcestershire sauce. Mix until smooth, and pour over steaks. Cover pan with aluminum foil.