Place roast in slow cooker. Sprinkle dried onion soup over roast. Pour cream of mushroom soup over. Cook on low 10-12 hours or on high about six hours, depending on size of roast. If you have time, 1/2 to one hour before serving, pull roast into pieces with two forks or slice with a knife and mix into the onion/cream of mushroom soup gravy. If not, use as is. Serve with noodles or mashed potatoes. Number of servings depends on the size of the roast. May add extra onion soup/cream of mushroom soup for extra gravy.