In a large pot over medium heat, saute the ham until it begins to brown and release some fat and moisture into the pan, about three minutes.
Add the carrots and celery and saute until they begin to soften, about four minutes.
Add the leeks and saute until they begin to soften, about two minutes.
Add the garlic and saute until fragrant, about one minute.
Add the chicken stock, water, thyme, bay leaves, and ground black pepper. Stir, raise heat to high and boil.
Lower heat and simmer mixture, uncovered for 50 minutes.
Add sweet potatoes, raise heat and bring to a boil. Lower heat to simmer and cook until sweet potatoes can be pierced easily with a fork 15-20 minutes.
Garnish with chopped parsley and serve!