Remove skin and trim excess fat from pork leg, leaving only a thin fat covering.
Place pork, fat side up, on rack in large roasting pan.
Preheat oven to 350°F.
In small bowl, combine salt and next 5 ingredients.
With hands, rub spice mixture over pork.
Insert meat thermometer into center of thickest part of pork, being careful that pointed end of thermometer does not touch bone.
Roast pork 3 hours.
Cover pork loosely with a tent of foil.
Continue roasting about 1 hour longer or until meat thermometer reaches 150°F.
Meanwhile, in 1 quart saucepan, heat apple jelly and balsamic vinegar over high heat to boiling; boil 2 minutes.
Remove saucepan from heat; set glaze aside.
4 When pork has reached 150°F., remove foil and brush with some glaze.
Continue roasting pork, brushing occasionally with remaining glaze until meat thermometer reaches 160° to 170°F., a total of about 5 hours. (Pork near bone may still be slightly pink.)
When pork is done, place on large platter; let stand 20 minutes for easier slicing.
Garnish with fresh thyme.