A Seville Orange Marmalde or a 50:50 Marmalade of Oranges and Lemons works wonderfully as a glaze prior to roasting.
Simply coat surface of roasting meat with marmalade, stud with cloves (for ham), and bake. Adding a little water to the bottom of the roasting pan will help prevent any marmalde from burning.
If your marmalde is particularly thick dilute or soften with boiling water (or water and whisky) prior to application.