Active Time

　　45 min

　　Total Time

　　45 min

　　This soup was inspired by a meal at the Copenhagen microbrewery Nørrebro Bryghus. (Who knew breweries could be fine-dining destinations?) Lager lends a malty richness to the velvety broth, thick with mussels; cold chopped avocado and tomato mingle with the heat, bringing the whole spectrum of flavors into sharper focus.

　　

Ingredients

Makes 6 servings

　　1 1/2 pounds leeks (3 medium; white and pale green parts only), quartered lengthwise, then sliced crosswise

　　2 tablespoons unsalted butter

　　4 (3-inch) sprigs fresh thyme

　　1 (12-ounce) bottle lager

　　1 1/2 cups water

　　3 pounds mussels (preferably cultivated), scrubbed well and beards removed if attached

　　1 cup half-and-half

　　1/4 teaspoon salt

　　1/4 teaspoon coarsely ground white pepper

　　1 (8-ounce) firm-ripe avocado

　　18 very small grape or pear tomatoes (1/4 pound), halved

　　3 tablespoons coarsely chopped fresh dill

　　

Step 1

Wash leeks in a bowl of cold water, agitating them, then lift out leeks and pat dry.

　　

Step 2

Cook leeks in butter in a wide 5-quart heavy pot over moderate heat, stirring occasionally, until softened, 5 to 7 minutes. Add thyme and cook, stirring, 1 minute. Stir in beer and water, then increase heat to moderately high and bring to a boil. Add mussels and return liquid to a boil, partially covered. Cook, completely covered, stirring occasionally, just until mussels open wide, checking frequently after 4 minutes and transferring to a large bowl. (Discard any mussels that remain unopened after 8 minutes.)

　　

Step 3

Working over a bowl, remove mussels from shells and put in bowl (discard shells along with any clinging leeks). Pour any cooking liquid accumulated in bowl back into pot.

　　

Step 4

Pour cooking liquid through a sieve lined with a double layer of cheesecloth or dampened paper towels into a 2-quart heavy saucepan. Stir in half-and-half, salt, and white pepper, then heat over moderately low heat until hot (do not let boil). Stir in mussels and heat until just warmed through.

　　

Step 5

Meanwhile, halve avocado, then peel 1 half (wrap remaining half tightly in plastic wrap and reserve for another use). Cut into 1/2-inch cubes, then toss gently with tomatoes and dill in a bowl.

　　

Step 6

Divide soup among 6 shallow bowls and spoon some avocado mixture into each. Serve immediately.

　　Cooks' note:

　　Soup, without half-and-half, can be made 1 day ahead and cooled completely, uncovered, then chilled (with shelled mussels in soup), covered. Remove mussels and reheat soup over moderately low heat before adding half-and-half and then proceeding with recipe.