Combine first 3 ingredients; dredge roast in flour mixture. Brown roast in hot oil in a large Dutch oven. Pour 5 cups water over roast. Bake at 325° for 3 hours or until tender. Baste roast with pan drippings at 30 minute intervals.
Remove roast to serving platter. Combine 2 tablespoons flour and 2 tablespoons water; stir into pan drippings. Cook over medium-high heat, stirring constantly, until thickened and bubbly. Serve gravy with roast.