Place venison in a zip-top plastic bag or other sealable, nonreactive container. Combine Port, orange peel, pepper, allspice, bay leaf, and thyme, and pour mixture over the venison. Seal and refrigerate. Allow venison to marinate overnight, turning occasionally.
Preheat oven to 400 degrees F.
Remove venison from the marinade, reserving marinade. Season all sides of the loin with salt and freshly ground black pepper. Heat the olive oil in a large, oven-proof skillet over high heat. Sear the loin in the hot oil on all sides (1 to 2 minutes). Place the skillet in the oven and bake for 17 to 20 minutes or until desired degree of doneness. The venison will be medium-rare when it reaches 125 degrees F on an instant-read thermometer. Remove the venison loin from the skillet and allow meat to rest for 10 minutes before slicing.
Add 1 tablespoon of butter to the skillet used to brown the venison. Heat over medium-high heat until melted. Add shallots and garlic. Cook, stirring constantly, for 30 seconds or until softened. Add reserved marinade, sugar, and cinnamon stick to the shallot mixture. Bring mixture to a boil and cook until mixture is reduced by half, about 3 to 4 minutes. The sauce should be thick and syrupy. Add demi-glace and gooseberries, and bring to a low simmer. Cook sauce at a low simmer until berries are softened and the sauce is thickened and coats the back of a spoon, 5 to 7 minutes. Remove the orange peel, bay leaf, thyme, and cinnamon stick from the sauce. Adjust seasonings with salt and pepper. Remove the sauce from the heat and stir in the remaining 3 tablespoons of butter. Serve warm with sliced venison.
Yield: 4 to 6 servings