In a Dutch oven, heat 1 tablespoon oil over medium-high heat. Toss pork tenderloin with 2 tablespoons flour, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Add meat to the pan, and brown, turning occasionally, about 6 minutes. Transfer to a plate.
Reduce heat to medium-low, add remaining 1 tablespoon oil, onion, and caraway seeds, if using, and cook until onion softens, about 3 minutes. Stir in remaining 1 tablespoon flour. Stir in stock, water, mustard, cabbage, potatoes, and 3/4 teaspoon salt. Bring to a boil, reduce heat, and simmer, covered, for 15 minutes. Add apples, and continue cooking, covered, for 10 minutes.
Just before serving, stir in reserved pork cubes, any juices that have accumulated on the plate, and chopped parsley. Simmer stew gently until pork is heated through, about 2 minutes (cooking it longer will make it tough).