Heat the oven to 400°F and grease a 9-by-13-inch dish. Shred mozzarella and cheddar; set half aside for the top.
Cook pasta in a large pot of water according to the package until just al dente. Drain.
Whisk coconut milk, arrowroot, salt, pepper and garlic powder. Melt ghee in a deep pan; add the milk mixture and soft goat cheese. Simmer gently until thickened.
Gradually stir in half the shredded cheese, remove from heat and mix until melted. Fold in pasta, transfer to the dish and add remaining cheese.
Cover and bake 15 minutes. Uncover and broil 3–4 minutes, watching closely. Scatter with chives.
Nutrition is an estimate per stated serving, based on the source recipe. Brands and portion sizes affect the result.For gluten-free preparation, check all packaged ingredient labels, including broth, seasonings and toppings.Inspired by Michelle Hoover.