Add garlic, brown duck breasts on both sides, remove and set aside. Add remaining butter and reduce heat to simmer. When the butter is melted add orange rind, tomato paste, chicken broth, orange juice, and honey. Stir over moderate heat until mixture comes to a boil. Add pineapple and peach, bring back to a boil.
Place breasts in a large pot and coat with sauce.
Cook over low heat about 20 minutes. Arrange breasts on heat-proof serving platter. Whisk whipped cream into sauce and add mushrooms. Spoon sauce over breasts and place in the broiler. Brown lightly and serve.