Preheat the oven to 300 degrees.

Place the ham in an oven bag, this will help to cook it while retaining all of it's juices.

Place the ham in a roasting pan, on a rack to keep it up off the bottom of the pan.

Cook for about 10 minutes per pound at 300 degrees. Preferably, use a thermometer and cook to 110-120 degrees.

Remove the ham and raise the oven to 400 degrees.

Cut the bag and remove it from around the ham, being careful that any juices go into the pan.

Cut the top of the ham with a knife, in a cube pattern with several cuts across the ham in two directions.

Drizzle the top of the ham with yellow mustard and spread it around with a basting brush.

Sprinkle the ham with black pepper. Then, sprinkle the ham with brown sugar, pressing it down into the cuts on the ham.

Place the ham back into the 400 degree oven for 10-15 minutes to brown the top.

Remove the ham and let it stand, covered with foil, for 10 minutes.

While the ham is standing, pour the juice from the pan into a bowl and whisk the can of soup into the pan juices to make the gravy.