Step 1

Gather all the ingredients.

Step 2

First, make the dashi. Add the water and dashi packet to a saucepan, and bring it to a simmer on medium heat. Let it steep for 2-3 minutes on medium-low heat. Remove from the heat and let the saucepan cool over a bowl of iced water. For vegans/vegetarians, you can make Kombu Dashi.

Step 3

On a baking sheet lined with aluminum foil, spread the miso paste.

Step 4

Toast the miso in a toaster oven or the oven broiler for several minutes (8 minutes for my toaster oven) until the surface is slightly charred. Remove from the toaster/broiler and let cool.

Step 5

Add the toasted white sesame seeds to a Japanese mortar, reserving some sesame seeds for garnish later. Using a Japanese wooden pestle, grind the sesame seeds.

Step 6

Add the toasted miso to the mortar and set it aside (we'll mix them with the chilled dashi later).

Step 7

Peel the cucumber skin in stripes by alternating peeled and unpeeled strips down the length of the cucumber. Then, thinly slice it.

Step 8

Transfer the cucumber slices to a tray or plate and sprinkle with the salt. Gently rub the cucumber slices with your hands. The salt will draw out the moisture from the cucumber slices and make them crisp. Set aside for 5 minutes.

Step 9

Remove the stems of the shiso leaves and roll them up. Cut them into julienned strips. Set aside.

Step 10

Break up the cooked salmon into smaller pieces. Squeeze the cucumber slices to remove the moisture. Keep all the ingredients on a tray or plate.

Step 11

When the dashi is cold and the toasted miso is no longer hot, pour a small portion of the dashi into the mortar. Using a silicone spatula or spoon, stir well to dissolve the miso in the stock.

Step 12

Once the miso is dissolved completely, add the rest of the dashi and mix it all together.

Step 13

Add the cubed tofu (the Japanese usually cut tofu while holding it on their palm, but you can cut it into ½-inch (1.3 cm) cubes on a cutting board first). Add the salmon pieces.

Step 14

Add the cucumber and shiso leaves. You can chill the soup longer in the refrigerator or you can serve it immediately in individual bowls. Typically, Cold Miso Soup is served with steamed rice. Some enjoy it by pouring the soup over rice or vice versa.

Step 15

You can keep the leftovers in an airtight container for 2-3 days. You do not need to reheat. Enjoy it chilled.