Preheat your oven to 375 F.
Cut each squash in half, but leave the seeds in. Place cut ends up on a baking sheet and roast them for about 50 minutes to an hour, long enough so that the flesh is fork-tender. Remove once cooked and let cool for several minutes.
2 acorn squash
Meanwhile, in a medium skillet over medium heat, saute the onions in the cooking fat. Cook for close to 10 minutes, until the onions are translucent and begin to be golden brown.
2 onions
Add the garlic to the skillet, followed by the coriander, nutmeg, salt, and pepper. Continue to cook for about 2 minutes.
3 cloves garlic, 1 teaspoon ground coriander seed, ½ teaspoon nutmeg, Sea salt and freshly ground black pepper to taste, 3 tablespoon clarified butter
Remove the seeds from the squash and discard. Spoon out the tender flesh and discard the skin. Roughly mash up the squash and add it to the skillet. Mix well. Only leave on the heat long enough to blend flavors.