In dutch oven over medium-high heat, heat oil. Sear roast on all sides until well-browned. Pour off fat.
Add mushroom soup, 1 cup of the water, and the soup mix. Heat to a boil. Cover and cook over low heat 1 1/2 hours.
Add potatoes and carrots, cover and cook for 1 more hour or until roast is done (150 - 160 degrees. Roast continues to cook after heat is shut off.)
Remove roast and vegetables to serving platter. Mix the flour and remaining water until smooth. Gradually stir into soup mixture. Cook until mixture boils and thickens, stirring constantly. Serve this gravy with the roast and vegetables.