Honey Ham

0 Preheat the oven to 350°F.
1 Line a roasting pan or a large rimmed sheet pan with three layers of aluminum foil. This will be used to wrap the ham and hopefully prevent leaks. 
8 Place the ham face down on the prepared pan. Cover completely with the foil. You may do this loosely, but you need to ensure the bottom and sides are sealed well so it does not leak because the sauce is very sticky.
9 Bake the wrapped ham for 120 minutes (or 2 hours).
2 Make the glaze in a saucepan. Combine the mustard, sugar and butter. Heat over medium-low heat until combined, then stir in the honey. Turn off the heat, and let sit for 10 minutes.
3 When the ham has finished its first bake, take it out of the oven and unwrap the top half of it.
4 Turn up the heat of the oven to 425°F.
5 Brush the glaze over the uncovered ham, and place in the oven to bake for an additional hour (to 1.25 hours). Every 15 minutes, open the oven and liberally coat the ham in glaze as it bakes.
6 After you've glazed the ham 4 times and baked a final time, remove the ham from the oven.
7 Let cool for 15 minutes, then carve and serve warm!