Preheat the oven to 400 degrees F.
Pat the pork tenderloin dry with a paper towel. Season it all over liberally with salt and pepper. Season it with garlic powder and smoked paprika.
Heat the olive oil in a cast iron (or oven safe) skillet over medium-high heat. Add the tenderloin and seared on all sides until deeply golden brown.
While searing, whisk together the cider and maple syrup. Pour the mixture into the skillet and let it bubble up. Reduce it to the simmer and cook for 1 to 2 minutes.
Transfer the pan to the oven and roast for 15 minutes, then take the internal temperature. I like mine to be at at least 155 degrees F.
Remove the pan and transfer the pork to a plate to rest. You can also pour the juice/glaze into a bowl to use it for the pork. After the pork rests for 15 to 20 minutes, you can slice it and drizzle the juice on top.
While the pork rests, heat that same pan over medium heat. Add the olive oil. Add in the cabbage, apples, red onion and walnuts. Toss well. Add a big pinch of salt and pepper. Stir together the vinegar, maple syrup and dijon. Add in the nutmeg. Pour it in and toss again. Cook for just a few minutes until the slaw is warmer and slightly soft but still crisp.
Serve the slaw immediately with the pork tenderloin. Enjoy!