1Heat the oil in a large pot over medium-low heat. Place onions in pot and cook 20 minutes, stirring occasionally until very tender and golden brown.
2Mix celery root, potato peels, carrots, mushrooms and squash into pot. Season with salt. Continue cooking 45 minutes or until vegetables are very tender and golden brown.
3Pour water into pot. Bring to a boil. Reduce heat to low and simmer 30 minutes, stirring occasionally. Strain out the solids, taste for sufficient salt and voila! Your stock!
Footnotes
Notes
You can saute a few onions and garlic, add the stock, a couple of bags of frozen peas, a couple of mint leaves, blend it up, add a touch of cream, and a highly elegant and lovely bright green soup is on its way to your tummy.
Many types of vegetables may be used to prepare the stock. Things to avoid are broccoli, cauliflower, kale, cabbage -- you get the picture.