Preheat oven to 425°F.
Place halved potatoes in a microwave-safe bowl with 1 tablespoon water. Cover loosely and microwave on high for about 4 minutes, until slightly tender but still firm. Drain.
Pat pork dry and season with salt, pepper and garlic powder.
Heat 1 tablespoon olive oil in a large oven-safe skillet over medium-high heat. Sear pork for about 2 minutes per side until golden. Transfer to a plate.
Reduce heat to medium. Add remaining oil as needed, followed by shallot, apples and thyme. Cook for 1–2 minutes.
Add potatoes to the skillet.
Whisk Dijon, maple syrup, apple cider vinegar, garlic, chicken broth, salt and pepper. Pour into the skillet and scrape up the browned bits.
Return pork to the skillet and spoon some sauce over the top.
Transfer to the oven and roast uncovered for 12–16 minutes, or until the pork reaches 145°F internally.
Transfer pork to a cutting board and rest for 5–10 minutes.
Stir butter into the warm pan sauce.
Slice pork into medallions and return to the skillet. Spoon sauce over the pork and garnish with additional fresh thyme.