Spicy Beef Vegetable Stew

Ingredients:
1 pound ground beef
1 cup chopped onion
1 (30 ounce) jar meatless spaghetti sauce
3 1/2 cups water
1 (16 ounce) package frozen mixed vegetables
1 (10 ounce) can diced tomatoes and green chilies
1 cup sliced celery
1 teaspoon beef bouillon granules
1 teaspoon pepper

Directions:
In a skillet over medium heat, cook beef and onion until meat is no longer pink; drain. Transfer to a slow cooker. Stir in the remaining ingredients. Cover and cook on low for 8 hours or until the vegetables are tender.