We have found sparkling cider to be the most effective and quickest option for marinating pork. Its acidic properties permeate the meat quicker, resulting in a more tender and flavorful pork.

Remove the pork from the refrigerator and using a very sharp knife, cut the tenderloins into 1-½-inch thick slices. Using the heel of your hand, flatten each slice lightly to approximately an inch.

Arrange the pork medallions in a shallow baking dish, and pour 1 cup of apple cider over the meat, ensuring all pieces of meat are covered in liquid. Cover with plastic wrap and marinate at room temperature for 25 to 30 minutes.

To cook sweet potato mixture: While the pork is marinating, prepare the sweet potatoes. In a large nonstick skillet over a moderate heat, add 2 tablespoons of oil. When shimmering, add the onions and cook, stirring occasionally, until tender, about 7 minutes. Add the garlic and cook until fragrant, about 1 minute. Add the sweet potato and cook, stirring occasionally, until just starting to soften, about 10 minutes. Stir in the apples and continue to cook until starting to soften, about 7 minutes. Add the remaining apple cider, broth and rosemary and cook until the vegetables are tender, about 10 minutes. Stir in the lemon juice, taste and season with salt and pepper. Set aside and keep warm.

To cook the pork medallions: Remove the pork from the marinade, pat-dry with paper towels and season with salt and pepper. Place a large nonstick skillet on the stove over a moderate-high heat and add the remaining oil. When the oil is shimmering, add the pork medallions and cook, turning once, until the meat registers 145 degrees on an instant read thermometer, about 5 minutes. Using tongs, transfer to a plate and let rest for 5 minutes prior to serving.

To serve: Divide the cooked pork medallions between 4 warmed dinner plates. Reheat the sweet potato and apple mixture and place over the meat. Serve immediately.