Preheat oven to 400 degrees and place cast-iron skillet in oven to preheat. Remove pork chops from fridge and let sit at room temperature 20 minutes.
Combine all ingredients for the romesco sauce in food processor. Process until fairly smooth. Season with salt and set aside.
For the pork chops, carefully remove skillet from oven and put over medium high heat on stove with a few tablespoons olive oil. Liberally salt and pepper pork chops and carefully slide into skillet. Let cook to sear 2 to 3 minutes, then flip pork to sear on other side 1 minute or so. A golden crust should form. Place skillet in oven to cook for 10 minutes until done.
Serve hot with romesco sauce on side or dolloped atop. Remaining romesco sauce can be saved in fridge for three days.