In a large pot, over medium heat, add the olive oil. When the oil is hot, add the onions and saute for 2 minutes. Season with salt and pepper. Add the sausage and continue to saute for 2 minutes. Stir in the garlic and herbs. Add the potatoes and stock. Bring the liquid to a boil and reduce to a simmer. Simmer the soup for 30 minutes. Add chopped parsley and season the soup with salt and pepper.