Chilled Edamame Noodle Soup

From the garden

• 3 cups shelled edamame, shelled from about 2 pounds of pods
• 1 medium cucumber, seeded and cut into fine matchsticks
• 1 medium ripe tomato, cut into thin wedges

From the pantry

• 3 tbsp tahini · stands in for the ground toasted sesame the broth is built on
• 12 oz thin wheat noodles (somyeon)
• 1 tsp toasted sesame oil (optional) · a few drops at the table
• 1 tsp sugar (optional) · some cooks add a pinch to push the beans sweeter
• salt · to taste; the broth is properly salted at the bowl

1. Boil the shelled edamame in well-salted water 4–5 minutes, until a bean crushes easily between your fingers. Drain and cool them under cold running water, which is what keeps the broth bright green rather than khaki.
2. Blend the cooled beans with the tahini, the sugar if using, and 3 cups of very cold water until completely smooth, a full 2 minutes in a strong blender. Pass it through a sieve for the silkiest texture.
3. Chill the broth at least 30 minutes, or blend in a handful of ice to shortcut it. Kongguksu is served genuinely cold, not merely cool, and it thickens slightly as it sits.
4. Cook the noodles in plenty of boiling water until just tender, 3–4 minutes, then rinse hard under cold water, rubbing the strands with your hands to wash off the surface starch. Drain very well.
5. Divide the noodles among four bowls, pour the cold broth around them, and top with the cucumber matchsticks and tomato wedges. Salt each bowl at the table and add a few drops of sesame oil.