Preheat oven to 200°C.
Prep the ham by peeling back the skin and discarding it, leaving just the "handle" covered in skin.
Score the fat on the ham in a diamond pattern being careful not to cut into the meat.
To make the Char Siu glaze, place all ingredients in the Thermomix bowl. Chop 20 sec/speed 8. Heat 4 min/60℃/speed 1 to form a syrup.
Glaze the ham by brushing the char siu generously over the scored fat and place in the oven. Re-glaze every 10 minutes until your ham is caramelised.
Any leftover glaze can be cooked longer and used as a sauce.