-
1
Place the potato in a small pot, and add water to cover by 1 to 2 inches. Bring to a boil over high heat, then reduce the heat until it's just high enough to maintain a simmer. Cook until the potato is tender when pierced with a knife. Drain and let the potato cool to room temperature.
-
2
While the potato is cooking, take 5 of the hard-boiled eggs (set aside the remaining egg for garnish), and separate the yolks from the whites. Dice the whites into 1/3-inch pieces, and set aside.
-
3
Place the yolks in a large bowl, and mash them with a fork. Add the mustard, and keep mashing to form a uniform, lump-free paste. Whisk in the smetana, then the kefir, then the water. Season to taste with salt, and refrigerate.
-
4
In a large bowl, mix together the reserved egg whites, potato, salo, radishes, cucumbers, scallions, and dill. Mix well, and season with salt and pepper. Place 3/4 cup of the salad mixture into soup bowls. Add 1 cup of the kefir mixture into each bowl, then top with slices of the reserved hard-boiled egg, scallions, and dill. Serve very cold. If you're not eating all the okroshka at once, store the kefir base and the prepared vegetables separately, and combine them just before serving. The kefir mixture will keep for up to 1 week, but the vegetables are best mixed up the day they are to be used.