Actually it's fairly easy and produces beets (as they're known here in the U.S.) with a nice color as well as texture.
Simply trim the tops back to about 2 inches in length (leave the long bottom tap root on) and place them in boiling water (a few at a time) until fork tender, just as described by muff13 , then immerse them in a sink full of ice water to stop the cooking. The tops and the skins will just almost fall off. Rinse and dry and leave the smaller ones (less than 2 inches in diameter) whole, but either slice the larger ones or at least quarter them. I, then, like to place them on a aluminum (excuse, me... aluminium) covered cookie sheet (what ya'll call biscuits) with our touching each other and pop them into your freezer. You can then place them in a ziplock freezer bag and they'll be good for probably 2 or three months.
Alternately, after they're frozen (only takes a couple of hours) we use a food vacuum sealer which will make them last until next spring!