Pat the pork loin dry and slice it into 1-inch thick medallions. Season with salt and black pepper. Peel and dice the onion. Core and dice the apple. Wash and dice the potato into 1-inch cubes.

Heat olive oil in a large skillet over medium-high heat. Add pork loin medallions and sear for 2-3 minutes per side until golden brown. Remove pork from skillet and set aside.

Add diced onion and potato to the skillet. Sauté for 5 minutes until onions soften.

Stir in the drained sauerkraut, diced apple, mustard, caraway seeds, and bay leaf. Add water if needed to prevent sticking. Bring to a simmer, then reduce heat to medium-low, cover, and cook for 5-7 minutes, or until potatoes are tender.

Return the seared pork loin to the skillet, nestling it into the sauerkraut mixture. Cover and cook for another 2-3 minutes, or until pork is cooked through. Remove bay leaf before serving. Serve hot.