Beets
I like beets, but they're just one of those things that I rarely prepare for myself. Fortunately, I've found that the sous vide machine is excellent for preparing beets.
Peel and slice one large red beet. Add to a vacuum bag, along with salt, pepper, and a little olive oil. Vacuum seal.
Sous vide for 45 minutes at 180°F.
The beets are very tender but are still firm and maintain their shape at this length and temperature. Once cooked they'll keep well in the refrigerator in a sealed container.