Crockpot Roast

1 pot roast, lean, boneless, about 2 to 3 pounds
1 tablespoon vegetable oil
1 medium onion, sliced
4 medium sweet potatoes, about 1 1/2 pounds, peeled and quartered (enough for 4 to 6 people)
1/2 cup water
1 1/2 teaspoons beef bouillon granules or beef base
1/4 teaspoon celery seed
dash ground cinnamon
1/4 teaspoon ground black pepper
2 tablespoons cornstarch combined with 2 tablespoons cold water, optional

Trim roast. Heat oil in a large skillet and brown roast on all sides. Browning the roast is optional, but does enhance the flavor a bit. Drain fat from skillet. Place sliced onion in crockpot; top with sweet potatoes. Place meat on vegetables. In a cup, combine the 1/2 cup water, beef bouillon granules, celery seed, cinnamon, and pepper. Pour over roast. Cover and cook on LOW for 8 to 10 hours, until meat is tender (or cook on HIGH for 4 to 5 hours). Remove beef and vegetables to a serving dish and keep warm.

Skim fat from juices and serve with the beef and vegetables. If desired, pour 2 cups of the cooking liquid into a 2-cup measure. Add enough water or broth to make 2 cups. Put the 2 cups of juices into a saucepan and stir in the cornstarch and water mixture. Cook on medium-low until thickened and bubbly. Serve with roast and vegetables.