Saute mushrooms & shallots in 4 Tablespoons of butter ina large skillet. Add wine; cook over high heat until reduced to half. Pour mixture into 3 litre casserole. Dredge venison lightly in flour & saute in remaining 2 Tablespoons butter. Add tomatoes, pepper, potatoes & onions; saute for 5 minutes, stirring frequently. Add orange peel. Stir in flor. Add beef broth. Cook, stirring constantly, until mixture thickens. Boil 1 minute. Stir mixture into casserole; add bay leaf. Cover; bake at 180ºC . for 1.25 hours or until meat & vegetables are tender. Remove bay leaf before serving.