In a 10 inch cast iron skillet over medium heat combine olive oil, butter, and sliced onions. Saute, stirring occasionally, until onions become soft. This will take approximately 10 minutes.
Sprinkle 1 teaspoon granulated sugar and 1/2 teaspoon coarse sea salt over the onions. Add fresh thyme and bay leaf to the panto pan.
Continue sautéing over medium heat until onions become deep golden brown. Stir every few minutes to prevent onions from burning. This process of caramelizing the onions should take about 15 to 20 minutes.TIP: If color becomes too dark on some of the onions while still cooking, add a splash of white wine or beef broth to the pan and stir.
In the final minute or two of cooking, add minced garlic and saute for just a couple minutes. Be careful not to burn the garlic.
While onions are cooking, prepare the pork chops. Remove from packaging and pat with a paper towel to make sure they are completely dry.
Combine black pepper, garlic salt, ground thyme, and remaining 1/2 teaspoon sea salt in a small dish. Rub spice mixture onto both sides of the pork chops.
Remove caramelized onions from the skillet.
Without wiping out skillet, turn the heat to medium high and add pork chops. Sear on each side until browned, about 4 minutes on each side.
Preheat oven to 400 degrees F.
Remove pork chops from the skillet and set aside momentarily.
Place onions back into skillet and return to medium heat. Sprinkle with flour and sauté for 1 to 2 minutes to cook the flour.
Add white wine to onion mixture and simmer/stir for 2 to 3 minutes while the alcohol evaporates and the browned bits on the bottom of the pan loosen. If you are not using wine proceed with the next step.
Add beef broth to the onions and bring mixture to a simmer. Simmer for 2 to 3 minutes until the mixture thickens slightly and a deep brown gravy forms.
Nestle the pork chops down into the onion gravy and spoon some of the sauce up over the pork chops.
Top each pork chop with a slice of provolone cheese and a sprinkle of grated gruyere.
Transfer skillet to the oven and cook for 10 minutes until the cheese has melted and the meat registers an internal temperature of 145 degrees F.
Remove from oven.
Spoon onions and sauce over the pork chops.
Garnish with fresh thyme and serve.