1. Rinse meat and place in a 5- to 6-quart pan. Add broth, carrots, cloves, bay leaves, and peppercorns. Bring to a boil over high heat, cover, and simmer gently until meat is very tender when pierced, 1 to 1 1/4 hours.
2. Meanwhile, rinse mushrooms; trim off and discard discolored stem ends. In a 10- to 12-inch frying pan over medium heat, melt butter; add mushrooms and onions, mix, cover, and cook, shaking pan or stirring often, until mushroom juices have evaporated and vegetables are beginning to brown, about 15 minutes. Remove from heat.
3. When veal is tender, transfer meat and seasonings with a slotted spoon to the pan with the mushrooms and onions (mounding, if necessary); discard cloves and bay leaves if desired. Add lemon peel and cream to the broth in the 5- to 6-quart pan and boil, uncovered, over high heat until reduced to 3 cups, 10 to 15 minutes. Stir in parsley.
4. In a small bowl, blend cornstarch with 2 tablespoons water until smooth; stir into boiling veal juices. Add lemon juice and the meat and vegetables; stir gently until meat is hot, 2 to 3 minutes. Add salt to taste and ladle stew into wide bowls