The following is the recipe we have used on our family for the most wonderful smelling and tasting meat that I know of:

1 large fresh pork ham (or tenderloin if you do need such a large piece of meat).
4 large heads garlic, separated into cloves and peeled
3 or 4 cups sour orange juice
4 tablespoons oregano (or to taste)
black pepper to taste

Twenty-four to 48 hours before ready to cook, puncture holes throughout the pork and into each hole place a bruised clove or garlic.  Then rub the outside of the pork with oregano and black pepper.  In blender, combine sour orange juice, the remainder of the garlic cloves and oregano and blend until everything is well combined.  Pour over the pork and marinate in refrigerator until ready to bake. Several times while marinating, turn pork. Put pork in the baking dish into a clean large plastic bag to keep the flavor of garlic from getting into other foods stored in your refrigerator (a small garbage bag works well for this purpose). Place pork in a preheated 425 degree oven and bake for 25 to 30 minutes, then reduce temperature to 325 degrees and cook until pork is cooked and juices run clear.  Several times throughout the baking process, spoon the marinade and pork juices over the meat.   Let stand for at least 30 minutes before slicing.  After arranging on serving platter, pour some of the juices over the sliced pork and a put a gravy boat of additional juices on the table for those who love lots of those wonderful juices (like me).