Just as cucumbers and dill make a winning combination, beets and dill are just as tasty together, as most Eastern Europeans and Scandinavians would agree. This is yet another version of the weirdly bright pink soup known as borscht, which has infinite variations; save the beet greens for another dish. If cucumbers are not in season, leave them out.  This soup is uncooked and served at cool room temperature. If you want to serve it hot, put the soup into a non-reactive saucepan and heat it gently until hot through; serve immediately. It is best to use whole-fat buttermilk in this soup, or at least 1 1/2 % fat; do not use non-fat buttermilk. Sometimes I add up to 1 tablespoon of freshly grated horseradish root for a little kick. Borscht is often served with boiled potatoes, hard-cooked eggs, and extra minced dill for garnish.

Trim and scrub the beets and cook them in water to cover by 1 inch until they are tender, about 20 to 25 minutes. Refresh them under cold water and slide their skins off by rubbing them hard in the cold water. Grate the beets coarsely or julienne them in the food processor and put them into a large bowl. Add the cucumber, onion, garlic and 1/3 cup of the dill; squeeze the lemon over the vegetables, sprinkle lightly with salt and pepper, and toss well.

Sprinkle the toasted cumin and coriander over the vegetables and add the buttermilk and about 1 cup of the sour cream. Stir well to combine. Cover and chill for at least half an hour, or up to overnight.

To serve hot, remove from the fridge and gently reheat, stirring occasionally. Stir well and taste for seasoning; just before serving add the rest of the sour cream, stir well and adjust with salt, pepper or lemon juice.

To serve cold, remove from the refrigerator about 20 minutes before serving. Stir well and taste for seasoning; add the rest of the sour cream to loosen it up a little, adjust with salt, pepper or lemon juice. Garnish with the rest of the dill and serve at cool room temperature.