Wash and chopped vegetables. In a large stock pot, saute the onion in oil on medium heat for a few minutes. Add all ingredients into pot and bring to a boil. Then reduce heat and let simmer for 90 minutes with lid partially covered.
Let cool and strain the broth. Store in sealed containers, and use within 3 days. Or freeze for longer storage and later use.

1 tablespoon oil
1 large onion, roughly chopped
10 cups filtered water
2 parsnips, roughly chopped
3 carrots, roughly chopped
2 leeks, roughly chopped
4 cloves of garlic, crushed
1 tablespoon sea salt
1 handful fresh parsley
optional: 3 bay leaves