Assembly instructions: Combine first seven ingredients in a gallon resealable freezer bag; squish to mix. Seal well, label and freeze.
Cooking instructions: Thaw completely. Place in greased slow cooker on low for 8-9 hours. When roast is done, remove from slow cooker. Combine cornstarch and water. Pour by small amounts into slow cooker sauce until you reach desired consistency. Pour over roast. Makes 6 servings.