4leekswhite and pale green parts only, cleaned and sliced
1tablespoonfresh thyme leaves
4-ouncelog soft fresh goat cheese
Additional fresh thyme for garnish
Preheat oven to 400°F. Place butternut squash cubes in large bowl, and drizzle with oil, ½ teaspoon salt, and ¼ teaspoon pepper, and toss to coat. Spread squash cubes onto a large rimmed baking sheet, and roast until just tender and beginning to brown, stirring occasionally, about 35 minutes.
Meanwhile, in a large heavy skillet over medium-low heat, add oil. Once oil is hot, add leeks and thyme, and sprinkle with a pinch of salt and ¼ teaspoon pepper. Sauté until tender but not brown, about 15 minutes.
Coat 13x9-inch baking dish with a light drizzle of oil or cooking spray. Spread half of leek mixture over bottom of baking dish. Sprinkle with half of squash and half of goat cheese. Repeat layering with leeks, squash, and goat cheese.
The gratin can be made one day ahead to this point, cover and chill until ready to bake.
Preheat oven to 375°F. Pour milk evenly over gratin. Bake, uncovered, until gratin is heated through, about 30 minutes (40 minutes if previously chilled). Enjoy.