If using a large ham portion, cut it into 2 or 3 manageable chunks so it fits easily into your slow cooker. If you're starting with a tough cut, like a picnic shoulder ham, score the fat layer with a sharp knife.

In a small bowl, whisk together the chicken stock, brown sugar, Dijon mustard, onion powder, garlic powder, and pepper. Pour this mixture over the ham in the slow cooker.

Cover the slow cooker and cook on LOW for 6-8 hours, or on HIGH for 3-4 hours, until the ham is incredibly tender and easily pulls apart with a fork.

Carefully remove the ham pieces from the slow cooker (they will be hot!) and place them on a large cutting board. Using two forks, shred the ham completely. Discard any tough fat or bone. Return the shredded ham to the crockpot.

In a small saucepan on the stovetop, melt the 2 tablespoons of butter over medium heat. Whisk in the flour and cook for about 1 minute, until it smells slightly nutty, forming a roux.

Slowly pour in the milk (or half-and-half), continuing to whisk constantly for about 3-5 minutes, until the mixture thickens slightly and is smooth.

Pour the creamy roux over the shredded ham in the slow cooker. Stir well to coat every strand of the ham. Cook on HIGH for another 20-30 minutes, or until the sauce is hot and completely thickened. Stir in the fresh parsley just before serving.