Preheat oven to 400 F.
Preheat olive oil in a 10" cast iron skillet, or oven safe skillet over medium heat.
Remove pork chops from their packaging and pat dry with a paper towel.
In a small bowl mix together salt, thyme, garlic powder, and pepper. Sprinkle evenly over each side of the pork chops.
Place the pork chops into the skillet, searing each side of the pork about 3 minutes each, making sure it is browned all the way around the chop. (They will not yet be fully cooked.)
Remove pork chops from skillet and place on a plate, cover with foil, and set aside for now.
Add butter to the pan and raise the temperature to medium high.
Place into the skillet onions, xanthan gum, and 1/4 cup of beef broth, and sauté until the onions become very soft, about 20 minutes, stirring often.
Pour the remaining 1 cup of beef broth into the skillet.
As you allow the beef broth to come to a boil, use a wooden spoon or spatula to scrape the brown bits off the bottom of the pan.
Once the onion soup mixture comes to a boil, nestle the pork chops back into the skillet, and spoon the soup over the pork chops.
Evenly distribute the provolone and swiss cheese on top of each pork chop.
Place into the preheated oven, and bake about 10 minutes, or until the internal temperature of the pork chops is 160 degrees.
Remove heat and just before serving, spoon some of the onions over the pork chops.