Beef Stroganoff ala Campbell's

I needed something quick to whip up during weeknights as I get home at around 8pm and already hungry. Here's something I've been cooking ever since I got a hold of a Campbell's cook book in High School. Ingredients: 1/3 Kg Breakfast steak or sirloin cut in to strips marinated with salt and pepper 1 Tbsp vegetable oil 1 white onion 3 cloves of garlic 1 small can of button mushrooms (stems &