Remove bones from rabbit legs and butterfly open.
In a food processor, blend together walnuts, garlic, olive oil, rosemary and pepper until a paste is formed. Divide paste among 4 rabbit legs and roll each leg up. Tie each leg securely with butcher twine.
In a 10 to 12-inch saute pan, heat 4 tablespoons oil until smoking. Place rabbit legs in pan and saute on all sides. When fully browned, add onions, cherries and apricots and saute until softened, about 6 to 7 more minutes. Pour in Prosecco and bring to boil. Lower to a simmer and cover halfway. Cook 50 to 60 minutes until very tender, turning occasionally. If liquid dissipates, add 1/4 cup water at a time. Remove rabbit legs and cut the strings. Place on platter, top with cherry mixture and serve.