On a large baking sheet, roast onion, fennel and bones for about half an hour or until all are very darkened.
Add all of the broth ingredients to the slow cooker.
Bring to a simmer on high heat and then set to low for 24 hours.
When it is done, strain the broth with a sieve or skimmer.
In a large bowl, spiralize zucchini.
Add broccoli sprouts, meat, green onion, and white onion. Pour the broth over everything.
Serve with chopsticks and a soup spoon.