Rinse spinach, chop. In a pot, bring broth to a boil, add spinach, mix and cook for 1 minute. Remove from heat and cool (e.g., place in cold water), preferably chill.
Add kefir, chopped dill and chives, season with salt and pepper. Chill in the refrigerator if needed. Serve with egg and potatoes. Store in the refrigerator.