1. Wash the acorn squash well and cut in half, but do not pare.
2. Remove seeds.
3. Place the half squash cut side down in pan. Pour boiling water to 1/4 inch depth. Bake at 400 degrees for about 15 minutes, then turn the half so that the cut side is up.
4. When tender, remove from pan and scoop out the squash carefully, so that the shell remains intact. Mash and measure out 1/2 cup and mix with orange juice, nutmeg and butter, then return the mixture to the shell.
5. Reheat for a short time if necessary, and serve at once.
