A Fabulous Beef Stew

1 pkg. stew meat, about 1 1/2 pounds
1 packet Lipton beefy onion soup mix (I use plain onion soup)
1 1/2 tsp. beef bouillon
3 to 4 potatoes (cubed) (I peel them first)
4 carrots (sliced)
1 stalk celery (sliced)
1 can whole tomatoes, with juice (I use the big can -- 28 oz)
1 clove crushed garlic
salt and pepper to taste
2 tablespoons cornstarch mixed with about 1/4 cup cold water
Put all ingredients in a slow cooker on low heat for 8 to 10 hours. Taste and adjust seasonings. Add 2 tablespoons of cornstarch mixed with water. Turn heat to high and stir until thickened.