Sautéing is another fast way to make a meal, especially when the pan juices are turned into a sweet and savory sauce, as they are here. This comforting dish features an array of autumn ingredients—apples, fennel, and sweet potatoes—roasted in the oven to caramelize lightly and bring their sugars to the forefront. The sauce, which mingles apple cider with the meaty browned bits in the skillet, is sharpened with a bit of Dijon mustard to balance the sweetness.