(copied from Marion Cunningham’s The Supper Book, page 168)
4 medium-large beets, boiled** and peeled
1 1/2 cups sugar
1 large lemon
2 tbsp chopped fresh ginger
Put the beets in a food processor and process until coarsely chopped, or mash the beets by hand. Transfer the beets to a heavy-bottomed saucepan and stir in the sugar.
Cut, seed, and quarter the lemon. Put the pieces and the ginger into the food processor and process until finely chopped, or chop by hand. Add the lemon and ginger to the beet mixture and stir to blend. Cook over medium-low heat, stirring often, until the marmalade has thickened a little. This takes about 2 minutes – remember that the marmalade will get even thicker as it cools.
Put the hot marmalade into clean jars, cover and refrigerate when cool. This will keep for a month. For longer preserving, fill sterilized jars with the hot mixture, leaving 1/4-inch headspace. Put on the lids and tighten, and process in a boiling-water canner for 15 minutes.
** Instructions for boiling the beets are on page 11. They are pretty standard. But in the interest of sharing as much Marion Cunningham wisdom as I can, I’ll summarize them here. Basically, she advises that you cut off all but an inch of the beet tops and drop the beetings into boiling water for 30 minutes to an hour. Don’t trim, pare or otherwise remove the roots. When they are cooked, drain and cool them down in cold water. When you can, slip off the skins.