Please read Cooking Wildfowl and About Partridge and Grouse.
Pat dry:
With kitchen shears, cut out the backbone and discard or save for stock. Cut each bird into 2 halves by cutting through the breastbone. Place them in a deep bowl or baking dish just large enough to hold them.
Combine in a bowl:
Pour over the birds. Cover and refrigerate for 24 hours. If the marinade does not completely cover the bird, turn the pieces every so often.
Preheat the oven to 325°F.
Remove the birds from the marinade and pat dry. Strain the marinade into a medium saucepan and heat until steaming. Melt in a Dutch oven just large enough to hold the partridge over medium heat:
Add the bird halves skin side down and cook until browned. Turn skin side up, pour the marinade over them, and bake, covered, for 30 minutes. Uncover and cook until tender, 30 to 45 minutes. Transfer the birds to a platter and loosely tent with foil. Pour the pan juices into a small saucepan and boil over high heat until reduced to about 1 cup of sauce with a slightly syrupy consistency. Season to taste with:
Pour the sauce over the birds. Serve with: