Combine first 4 ingredients in a small saucepan. Bring to a boil. Remove from heat. Cover; set aside.

Place allspice and juniper in a spice or coffee grinder; process until finely ground. Sprinkle 1/2 teaspoon allspice mixture, 1/4 teaspoon salt, and pepper over venison. Melt margarine in a skillet coated with cooking spray over medium-high heat. Add venison; cook 5 minutes on each side or until browned. Reduce heat to medium; cook 3 minutes on each side or until desired degree of doneness. Remove venison from skillet; keep warm.

Add shallots and garlic to skillet, sauté 2 minutes. Add cherry mixture, 1 teaspoon allspice mixture, and 1/4 teaspoon salt; bring to a boil. Reduce heat; simmer, uncovered, until reduced to 1 cup (about 3 minutes). Combine water and cornstarch; add to cherry mixture. Bring to a boil; cook 1 minute, stirring constantly. Serve sauce with venison.

Note: You can substitute 1/2 cup cranberry juice for the port, if desired.