To make the mac 'n' cheese:
Preheat the oven to 375 degrees F. In a large saucepan, add the butternut squash, garlic cloves, thyme sprig, unsweetened almond milk, and stock. Cook until the butternut squash is fork-tender. Remove the sprig of thyme.
Place the squash mixture in a food processor or blender and puree until velvety smooth.
Meanwhile, cook the macaroni in salted water until it is al dente (semifirm). Drain and rinse with cool water.
Spread out the macaroni in a lightly greased 13-inch x 9-inch pan. Pour the squash puree over the noodles.
To make the breadcrumbs and bake:
Combine all the ingredients for the herbed breadcrumb topping.
Cover the mac 'n' cheese with foil, place in the oven, and bake for approximately 45 minutes. Remove from the oven and evenly spread the breadcrumb topping and Gruyere over the top. Transfer to the broiler and broil for 5 to 10 minutes, or until the cheese is brown and bubbly.
NotesWant to veganize this dish? Opt for veggie stock, swap in almond cheese, and add fresh herbs like thyme, parsley, or even double the garlic.