chunk of Finnish Lauantaimakkara-sausage
2 garden cucumbers or 1 small hothouse cucumber
large bunch of leafy green onions (spring onions) or scallions (green part only)
2 hard-boiled eggs
buttermilk or kefir
lemon soda (eg Sprite or 7Up)
sugar
salt

If you are not able to find genuine Finnish Lauantaimakkara-sausage (which is very likely to happen outside Finland), you can use any mildly seasoned, precooked and unsmoked or lightly smoked sausage, for example some Mortadella-type, extremely smooth-textured pink sausage with a subtle, creamy texture.

Peel the cucumber(s). Dice the sausage and the cucumber  —  there should be about an equal amount of both. Cut the onions' green part into thin slices and very finely grate the eggs.

In picture on right: The basic ingredients of okroshka, clockwise from upper left  —  grated hard-boiled egg, diced sausage, diced cucumber, sliced green onion.

Toss the ingredients together, season with sugar and salt (see the picture on the bottom right). Add enough buttermilk or kefir to get a thick soup-consistency. Cover and chill the soup thoroughly. Just before serving, add a dash of lemon soda to make the soup a little thinner and refreshingly "bubbly".

Additional information:
Okroshka is a traditional Russian cold soup usually made of kvas (= Russian homemade beer), vegetables, hard-boiled eggs, smetana and some cooked leftover meat, fish or crayfish.
In this recipe of my great-grandfather Aleksei, he replaced the kvas and smetana with buttermilk. Okroshka is ideal to be served chilled on a hot summer day.