STUFFING: In skillet, melt butter over medium heat; cook onion until tender. Stir in mushrooms, spinach, parsley, marjoram, sage, thyme, salt, and pepper to taste; cook for 2 minutes or until fragrant. Let cool. In bowl, combine pork, ham, bread crumbs and egg; add onion mixture and mix well. Fill pocket of each boned thigh with heaping tablespoon of stuffing and enclose with thigh meat. Secure with string. Place seam side down in single layer in greased baking dish. CUMBERLAND SAUCE: In saucepan, combine jelly, port, orange juice, lemon juice, orange rind, mustard and ginger; bring to boil, stirring constantly. Remove from heat. Pour 1/2 cup of the sauce over thighs. Bake, uncovered, in 350 degree oven for 1 1/4 hrs, basting occasionally, or until golden brown and juices run clear when chicken is pierced. Remove string, serve remaining sauce warm with chicken. Makes 8 to 12 servings. Recipe by: The Canadian Living Cooking Collection Posted to MC-Recipe Digest V1 #498 by sewin on Mar 31, 1997.