Wash and julienne the white part of the leeks.

Heat butter in a medium skillet over medium heat.

Saute the leeks for 5-6 minutes, until soft and translucent.

Add minced garlic and saute for 1 minute more.

Set the sauteed leeks and garlic aside.

Heat chicken broth with marrow bones in a large stockpot over medium heat.

Simmer for 10 minutes, removing any scum that rises to the top with a metal spoon.

Add chopped potatoes, carrots, reserved leeks, dill, salt, and pepper to the broth.

Continue to simmer the soup, uncovered, until the vegetables are tender but have not lost their shape, about 30 to 35 minutes.

Remove from the heat and cool for 10 minutes.

Remove the marrow bones with a slotted spoon.

Scrape the marrow from the bones with a small teaspoon and set aside.

Discard the bones.

Puree the soup in batches in a food processor fitted with a knife blade until smooth, colorful, and thick.

Return the pureed soup to the stockpot, blend in the reserved marrow, and season to taste.

Reheat over low heat and garnish with chopped curly parsley before serving.