Pasta e Fagioli Soup for the slowcooker/crockpot (12-14 servings)

2 lbs ground beef
1 onion, chopped
3 carrots, chopped
4 stalks celery, chopped
2 (28 ounce) cans diced tomatoes, undrained
1 (16 ounce) can red kidney beans, drained
1 (16 ounce) can white kidney beans, drained  (or sometimes I use one can of dark red, one can of light red)
3 (10 ounce) cans beef stock or one of those "liter" packages without MSG.
3 teaspoons oregano
2 teaspoons pepper
5 teaspoons parsley
1 teaspoon Tabasco sauce (optional)
1 (20 ounce) jar spaghetti sauce (I use Newman's Own with garlic or basil)
8 ounces rice pasta (we like Tinkyada)

Brown beef in a skillet.  Drain fat from beef and add to crock pot with everything except pasta.  Cook on low 7-8 hours or high 4-5 hours.   During last 30 min on high or 1 hour on low, add pasta.