I add everything and anything to chili and soup! Stay away from broccoli and cauliflower in big posts of food that aren;t going to get eaten right away, as they can make the whole pot very stinky (and you too, hehehe

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To chili I add some or all of the following:
onions, garlic, tomatoes, shredded carrots, celery, zucchini, peas, green beans and corn
I add all the same of the above to soups and also add:
cabbage (bok choy,napa,savoy,red,green...any kind!), spinach, kale, chard, potatoes, sweet potatoes, winter squash (any kind) and so on....