Heat a large
skillet over medium-high heat and stir in ground beef and onions. Cook
and stir until beef is crumbly, evenly browned, and no longer pink,
about 10 minutes. Drain and discard any excess grease.
mixture to a slow cooker. Stir in spaghetti sauce, water, mixed
vegetables, diced tomatoes, celery, beef bouillon, and pepper. Cover and
cook on Low until vegetables are tender, about 8 hours.