Pre-heat oven to 325 degrees F (163 C).

Remove ham from packaging and liberally spread salt and black pepper to the outside.

Cover ham tightly with two or three sheets of aluminum foil. Place wrapped ham in a roasting pan.

Bake ham in roasting pan for 1.5 to 2 hours or according to package directions (12 to 15 minutes per pound is a standard measure). 

When ham cooking time is almost done, in a small saucepan over medium heat, combine orange juice, brown sugar, spicy brown mustard and cornstarch and bring everything to a boil. Once boiling, reduce heat to low and simmer 2-3 minutes. Once time is up, remove pot from the heat and allow to cool.

When your ham has been cooking from 1.5 to 2 hours, remove it from the oven. Raise the oven temperature to 425 degrees F. 

Unwrap aluminum foil around ham, exposing the top side. With a basting brush or spoon, add glaze to the top of the ham. Try not to miss any spots and get an even covering with the glaze. 

Add roasting pan with glazed ham back into the oven and cook for another 15 minutes. 

Remove ham from oven and with the basting brush or spoon, add more glaze to the ham, trying again for even coverage. 

Allow ham to cool for 15 or 20 minutes before slicing. This helps to set the glaze. 

Slice ham and serve.