1. Place ham in crock pot.
2. In separate bowl, mix together brown sugar, mustard, and orange juice.
3. Pour mixture over ham, put cover on crock pot, and cook on HIGH for 1 hour.
4. Turn crock pot down to LOW temperature and cook for 6 to 7 hours.
5. Remove ham from crock pot and keep warm, and turn crock pot to HIGH.
6. Mix cold water and cornstarch in small bowl until cornstarch is dissolved.
7. Whisk cornstarch mixture into drippings in crock pot, cook until sauce begins to thicken, whisking several times.
8. Serve ham with thickened glaze spooned over slices.
If you are serving this ham at a buffet or potluck setting, slice the ham into serving size pieces and return to the crock pot after you've thickened the sauce. Put a large meat fork and a ladle next to the crock pot so people can spear a piece of ham and ladle their own sauce on top.
This is an excellent ham dish for special occasions and holidays. Both kids and grownups like this ham because it's sweet, but not overwhelming or 'sugary.' Enjoy!