Preheat oven for 350 degrees.
Combine first 5 ingredients in a bowl. Stir well and set aside.
Trim all fat from lamb. Make 12 deep slits on outside of lamb. Rub paprika mixture Into slits and over entire surface of lamb. Place on a rack in a roasting pan. Insert meat thermometer, making sure it does not touch fat or bone.
Bake uncovered in preheated oven for 45 minutes. Spoon orange marmalade over entire surface of lamb. Bake an additional 1 hour and 15 minutes or until meat thermometer registers 160 degrees (medium), basting frequently with orange marmalade. About 45 minutes before meat is done, sprinkle the potatoes with 1 teaspoon salt.
Place potatoes around meat. Roast until fork-tender, brushing with drippings. Place potatoes and meat on platter. Let stand 15 minutes before carving lamb. Makes 8 servings. Enjoy!
Note: The pan drippings can be used as a base for the gravy, or mint jelly is a nice accompaniment for leg of lamb.