How to Make It
Preheat the oven to 375°. Place the beets on a sheet of foil, sprinkle with salt and add the 1/3 cup of water. Wrap the beets lightly, set the package on a baking sheet and roast until tender, about 2 hours. Carefully unwrap and let cool.
Peel and coarsely chop the beets. Transfer to a large pot and add all of the remaining ingredients except the ice and vodka. Cook over moderately high heat, stirring occasionally, until the liquid has reduced to 2 cups, about 30 minutes. Strain the beet juice through a fine sieve and refrigerate until chilled.
Fill a cocktail shaker with ice. Add 2 3/4 ounces of the vodka and 4 ounces of the spicy beet juice and shake well. Strain into 5 chilled cordial glasses. Repeat three more times, using fresh ice each time.