In a nonreactive bowl, whisk together the parsley, onion, capers, salt, pepper, and vinegar. Whisk in the olive oil until evenly blended. Cover with plastic wrap and refrigerate for up to 24 hours.
Drain the beans, reserving the soaking water. In a very large castiron and enamel or other heavy casserole, heat the oil over low heat and cook the bacon for 3 to 4 minutes, or until most of the fat is rendered out. Remove 1 tablespoon of the fat and discard. Add the onions, paprika, leek, and carrot and continue cooking for 20 minutes, stirring occasionally, until all the vegetables are very soft. Add the garlic and cook for 5 minutes more.
Add the ham hocks, bay leaves, salt, pepper, and enough of the reserved soaking water to barely cover the ingredients. Bring the mixture to a boil and skim off the scum and fat that rise to the surface. Reduce the heat and simmer over low heat, partially covered, for 1 hour. Add the sausages and the beans and cook for 1 1/2 hours more, or until the beans are tender (you may need to add a little more water to keep the stew moist and juicy). Remove the ham hocks, remove and discard the rind and fat, and shred the meat. Return the ham to the pan and discard the bay leaves. Taste for seasoning and serve warm, with a small dollop of the salsa verde.
c.1997, M.S. Milliken & S. Feniger, all rights reserved