Latvian Aukstā Zupa (Cold Beetroot Soup)

Ingredients

• 500 g cooked beetroot (peeled and grated)
• 1 litre kefir (or buttermilk as substitute)
• 200 ml cold water
• 2 medium cucumbers (finely diced)
• 4 hard-boiled eggs (chopped)
• 5 radishes (thinly sliced)
• 3 spring onions (finely chopped)
• 2 tbsp fresh dill (chopped)
• 1 tbsp white vinegar
• Salt and freshly ground black pepper (to taste)
• 2 boiled potatoes (served separately for accompaniment)