For Cooked Wine Marinade: Slowly sauté the vegetables in the olive oil for 5 minutes without allowing them to brown. Add the remaining ingredients. Simmer, partly covered, for 20 minutes. Permit to thoroughly cool before using over venison.
For Marinating and Roasting the Venison: Place the venison leg in a large non-reactive pan which holds it snugly. Pour the marinade over the venison. Turn and baste the venison 3 or 4 times a day for 4 to 5 days at room temperature or up to 6 to 8 days if refrigerated