"Heat a large skillet over medium high heat. Add oil and meat to the pan. Spread the meat around the pan and break it up with a wooden spoon. Cook until meat is still just slightly pink (not browned), about 3 minutes. Add the tomato soup (undiluted), ketchup, Worcestershire sauce, vinegar, brown sugar, and mustard; stirring until well combined. Season with salt and pepper. Reduce heat to low and simmer, uncovered, stirring frequently, until sauce is thickened, about 8 to 10 minutes. Adjust seasonings. Spoon meat mixture onto hamburger buns, buttered and toasted or plain, and serve.Makes 8 to 10 servings."