1Preheat oven to 350 degrees F (175 degrees C). Spray a large casserole dish or Dutch oven with cooking spray.
2Combine brown sugar and flour in a bowl. Place Dijon mustard in a separate bowl. Heat olive oil in a large skillet over medium heat. Coat pork cubes with Dijon mustard and toss in brown sugar mixture to coat. Brown coated pork cubes on all sides in hot olive oil, about 3 minutes per side. Transfer browned pork into prepared casserole dish, leaving oil in skillet.
3Cook and stir onion and garlic in the hot skillet until onions are soft, about 5 minutes. Stir chicken broth, sherry, sweet potato cubes, black pepper, rosemary, thyme, and salt into onion; bring to a boil. Pour sweet potato mixture over pork and cover casserole dish.
4Bake in the preheated oven for 50 minutes; uncover and bake until pork is no longer pink inside and sweet potato cubes are tender, about 20 more minutes.
Footnotes
Tip
Aluminum foil helps keep food moist, ensures it cooks evenly, keeps leftovers fresh, and makes clean-up easy.