In a large saute or frying pan, melt 1/4 cup of the butter. Add the finely diced onion to the pan plus 1/2 teaspoon of sea salt and cook until browned and soft, about 7-10 minutes. Spoon out the caramelized onions and set aside in a separate bowl, leaving the melted butter behind in the pan.
In a large bowl or pie pan, make the seasoned flour for dredging the chops. Whisk the arrowroot flour, remaining 1 teaspoon sea salt, onion powder, garlic powder, cayenne, and black pepper together.
Place each pork chop in the flour and be sure to coat on all sides. Lay the dusted chops into the hot buttered pan and cook on high for 2-3 minutes each side (until golden brown). After both sides are browned, remove the chops from the pan and place them the bottom of a slow cooker.
To make the gravy, turn back to the saute pan now with some meat drippings, a little leftover melted butter, and some flour, add the remaining 1/4 cup of butter and stir until melted. Whisk in 2 tablespoons of the seasoned arrowroot flour mixture (it may start to form a paste at this point) and then whisk in the milk. Slowly whisk in the 2 cups of chicken or beef broth until the gravy has a smooth consistency (this may take a few turns of the whisk). If you feel like the gravy is too thin, whisk in one more tablespoon of the seasoned flour. Note that it will continue to thicken in the slow cooker.
Pour the gravy over the pork chops in the slow cooker, sprinkle the top with the caramelized onions, cover, and turn heat to medium. Cook in the slow cooker for 4-6 hours on low/medium heat.
When they're finished, carefully pull each chop out and place on a plate. Spoon extra gravy and onions over top and serve.