Broth time: 3 hrs, 20 min.
Soup time: 50 min
Total time: 4 hrs, 10 min + chill time
Makes 4 servings
3 Japanese OR 4 Persian cucumbers
1/2 tsp salt
1/4 cup toasted sesame seeds
1 cup dashi stock
3 tbsp miso
2 tsp sugar
5 leaves green shiso
2 cups cooked short grain brown rice
4 cups water
5-inch pieces of kelp
2/3 cup bonito flakes
**Vegan: Swap the bonito flakes with dried shiitake mushrooms but instead of adding it right at the end, boil the mushrooms for 10 minutes longer with the kelp to make the vegan dashi stock.
Dashi stock: soak kelp in water for 3 hours. Remove the kelp from the water and add the kelp water to a pot on the stove. Start the pot at a medium heat and bring to a rolling boil and turn off the heat. Add the bonito flakes and steep for 4 minutes. Set a bowl up with a strainer to pour the dashi stock through it to remove bonito flakes and kelp from the stock. Set aside.
Cut the ends of the cucumbers and use a mandolin or thinly slice them to about 1/16th of an inch thick or about 1.5mm.
In a medium bowl, toss the cucumbers with the salt and let sit for at least 30 minutes. Once they have started wilting, massage the cucumbers starting at a mild pressure and getting more firm as the cucumbers yields more water. The goal is to get them to a translucent state.
Once translucent, wring the water out of the cucumbers. Do this by taking them one handful at a time and squeeze them until no more water comes out (make sure to rotate the ball of cucumbers in your hand to make sure you squeeze all the cucumbers evenly). Once squeezed, place in a clean bowl and set aside.
In a food processor and blend the sesame seeds until they resemble fine sand. Add the 1 cup of dashi stock, miso and sugar and blend until smooth. Pour this mixture over the squeezed cucumbers.
Finely julienne the shiso leaves then add to the cucumber mixture. Stir everything to combine. Taste the mixture and add extra salt, if needed. Then, chill in the refrigerator until ready to serve.
To serve it, place a 1/2-cup of the hot rice in a bowl and ladle the cucumber and chilled soup mixture over it. Optional: if you like spicy food, sprinkle some of the shichimi togarashi (Japanese 7 spicy chili powder over the top, to taste). Enjoy!