The leek compote and the apples play so nicely off the sausage, and the goat cheese brings it all together lusciously! Serve with a bright, simple salad such as diced apples and walnuts in vinaigrette, or a celery-root slaw.
Make the filling:
Heat 1 Tbs. of the olive oil in a medium skillet over medium heat. Crumble the sausage into the skillet and cook it, stirring often with a wooden spoon, until no longer pink. As you cook and stir, break the sausage into small bits with the spoon and take care not to let it brown to the point of crustiness. Stir in the crushed fennel seeds. Scoop the sausage out of the skillet and transfer it to a paper towel–lined plate to drain.
Pour off the fat from the skillet, add 1 tbsp of the oil, and then the apples and a pinch of salt. Cook, stirring often, until the apples are tender and beginning to brown, 4 to 5 minutes. Transfer the apples to a large bowl, and add the sausage to the bowl as well.
Add the remaining 1 tbsp of olive oil to the skillet, and then add the leeks and 1/2 tsp salt. Cover and cook, stirring frequently, until the leeks are very soft, fragrant, and sweet, about 20 minutes. Season with pepper and more salt, if necessary. Add the leeks to the sausage and apples and gently toss them all together.
Finish the crêpes:
Position a rack in the center of the oven and preheat to 425°F. Butter the bottom of a 9-x-13-inch baking dish.
Lay the crêpes presentation-side down on a clean work surface. Divide the goat cheese equally among the crêpes, spreading it in a thick horizontal line across the center of each one. Spread about 1/2 cup of the sausage filling evenly over the cheese. To fold, pull the bottom edge of each crêpe up and over the filling and roll it up a half turn. Tuck in each side, and finish rolling up from the bottom. Arrange the crêpes seam-side down in a single layer in the prepared baking dish. They should be snuggled in tightly together. Brush the tops of the crêpes with the melted butter, if using, and sprinkle with the crushed fennel. Bake until heated through, 10 to 12 minutes, and serve right away.
Photo: James Baigrie