1. - Peel your vegetables, wash them well
2. - Bring a large volume of salted water to a boil.
3. - Place both types of potatoes in the boiling water.
4. - Cook for about 30 minutes.
5. (if the sweet potatoes are still a bit hard, add 15 more minutes of cooking)
6. Mash with a fork, or for a smoother texture, use a mixer!
7. Add nutmeg, sour cream, and serve piping hot.