Melt butter in a large, heavy pot over medium heat. Whisk in flour and cook for 1 minute. Whip Redi-Base Ham Base into milk. Add milk mixture to the pot in a slow, steady stream whisking to keep from lumping.
Cook for 3 to 5 minutes, until mixture, is thick and bubbly. Whisk frequently during this time.
Season with ¼ teaspoon pepper, and ¼ teaspoon nutmeg. Reserve ¾ cup of cheese and place remaining cheese in the pot and stir until melted.
Remove from heat and stir in cooked pasta and ham. Transfer to a lightly greased 9-by-13-inch baking dish. Top with remaining ¾ cup cheese.
Combine panko crumbs and melted butter in a small bowl and sprinkle on top of mac and cheese. Bake for 30 minutes.
Food for Thought
Why the Redi-Base Ham Base? Keep in mind, Cooking Bases are for flavoring. You can change the flavor of your sauce just by adding a different base. Because Cooking Bases need to be added to a liquid to produce stock, there is no rule that says that liquid must be water.
Use the Redi-Base Ham Base and cut down on the amount of ham used in the recipe. Not my preference, but if there is someone that needs to cut down on ham in their diet, this might be a better option.