Preheat oven to 350. Heat oil in a large heavy skillet over med-high heat. Brown steaks for 3-5 mins. on each side. While browning,season both sides with onion powder,garlic powder,salt and pepper. Transfer steaks to a 9x13" casserole dish,and sprinkle with chopped onion and sliced mushrooms.
In a small bowl,combine condesed soup,water,onion soup mix and worcestershire sauce. Mix until smooth,and pour over the steaks. Cover pan with aluminum foil. Bake in preheated oven for 90 mins.