2 cups brussels sprouts, trimmed
4 cups water
Bring a pot of salted water to a rapid boil. Cover, and boil for 5 minutes. Run a knife through one of the sprouts; if it slices through easily, turn off heat. Carefully pour brussels sprouts with water into a colander over a large empty soup pot. Immediately add sprouts to the blender, and add enough broth to half-cover them. Puree until velvety smooth and thin enough to drink from a mug or a jar, yet thick enough to enjoy in a bowl with a spoon. If the result is more of a puree than a liquid, add more broth in 1/2 cup increments until desired consistency is reached. Add salt to taste and blend again, if desired. Serve immediately.