How to Make It
Place the potatoes and carrots in a large pot and add 2 teaspoons salt and enough cold water to cover. Bring to a boil. Reduce heat and simmer until the potatoes are very tender, 20 to 25 minutes. Drain and return the vegetables to the pot.
Add the yogurt, butter, 1 teaspoon salt, and ¼ teaspoon pepper to the vegetables and mash to the desired consistency. Sprinkle with the dill.