Acorn Squash and Apple Puree

1. Remove the seeds and strings of the acorn squash, discard.
2. Arrange the squash, cut sides down, in a glass dish, prick the skin all over with the tip of a sharp knife, and microwave the squash at high power (100%) for 10 minutes.
3. Put the apple in a 1- or 2-cup glass measuring cup, cover it with microwave-safe plastic wrap and microwave it and the squash at high power (100%) for 4 to 6 minutes, or until they are tender.
4. Scoop out the squash discarding their skin, pour off any liquid from the apple, and force the squash and the apple through the medium disk of a food mill into a bowl.
5. Stiri in the butter, the nutmeg, and salt and pepper to taste.