Boil carrots to tender. Drain and return to pan, set aside.
Saute onions and garlic in butter until scalded
Combine carrots, onion and garlic in pan. Add chicken stock. Bring to boil. Reduce heat and simmer to mix flavors for 10 min.
Puree mixture in food processor or blender. Return to saucepan, stir in yogurt mix, dill and chives. Salt to taste. Warm until just heated through and serve.