Should I add vegetables and spices in the stock-making stage of pig-knuckle soup? I'm toying with the idea of making some soup - just a simple one.  The recipe call for boiling/simmering a pig-knuckle for about four hours together with a laurel-leaf.  Afterwards the stock/fond is strained, the meat stripped from the knuckle, and vegetables and the meat is put into the fond to make the soup - which should boil for another 10 minutes.

The thing is, I was wondering if I could do something more with it.  I thinking about adding vegetables, herbs and spices when cooking/simmering the knuckle, to add flavor to the stock and/or meat.

I was thinking root-vegetables like celery-root, beats and carrots... perhaps leek... perhaps onions, perhaps garlic - maybe after frying them lightly in some butter (before adding the water to cook the knuckle)...  I guess black pepper would be OK, but what about chili?  And what about some fresh herbs and spices?

My first thought would be to strain the stock and throw-away the out-boiled vegetables, since I'll be adding fresh ones to the soup anyway...  But could some (eg. the root-vegetables) or all be puraied in a mixer and added to the soup to make it "thicker" - and perhaps add flavor?

I you probably understand, I'm a lot better at eating food than making it, so any advice would be appreciated.
If you are going to cook a stock for 4 hours, the flavor of the vegetable will contribute to the overall flavor of the stock...but not be so great in vegetables themselves...and their texture will be very soft.  I would strain and de-fat the stock... then use the stock you created to build your soup.  Add vegetables at this point and cook just until the vegetables are cooked through.  This would provide both the best flavor and texture of the vegetables.  Use the same process if you want to puree some or all of the soup.