butternut squash, halved lengthwise and seeded
(16 ounce) package rotini pasta
tablespoons all-purpose flour
teaspoon dry mustard
ounces shredded white Cheddar cheese
ounces shredded Cheddar cheese
cup seasoned dry bread crumbs, or as needed
1Preheat oven to 400 degrees F (200 degrees C). 2 Place butternut squash, cut-side down, on a baking sheet. 3 Roast squash in the preheated oven until soft, 40 to 50 minutes. Remove squash flesh from skin and set aside. Reduce oven temperature to 375 degrees F (190 degrees C). 4 Bring a large pot of lightly salted water to a boil; cook the rotini at a boil until tender yet firm to the bite, about 8 minutes; drain. 5 Melt butter in a large saucepan over medium heat. Whisk flour and mustard into melted butter until smooth, about 1 minute. Gradually whisk milk into flour mixture until the mixture has the texture of heavy cream, 5 to 7 minutes. Remove from heat. 6 Stir butternut squash, white Cheddar cheese, and Cheddar cheese into milk mixture until cheese is melted. Stir rotini into cheese mixture. Pour cheese mixture into a 9x13-inch baking dish. Top with bread crumbs. 7 Bake in the preheated oven until bread crumbs are golden, about 10 minutes.