Step 1

Pass cherries through a food mill to extract all juices; or purée in a food processor and strain through a medium-mesh sieve, skimming surface of any foam. (Discard pulp, or reserve for another use.) Sprinkle garlic with 3/4 teaspoon salt, then mash into a very fine paste with the side of a knife. Stir into cherry purée.

Step 2

Refrigerate, covered, until very cold, at least 1 hour. (Purée can be made to this point and refrigerated up to 8 hours.) Stir chopped cilantro and dill into soup and season with salt; refrigerate 30 minutes more.

Step 3

Divide soup among 4 to 6 small bowls, and top each with cucumber, scallions, and herb sprigs. Serve with sour cream on the side.