How to Make It
Bring a medium pot of salted water to a boil. Stir in the rice and boil until almost tender, about 10 minutes. Drain.
Coat the salmon with the soy sauce and sesame oil.
In a large pot, combine the cooked rice, the cilantro stems, the ginger, salt, broth, and water. Bring to a boil. Reduce the heat and simmer, covered, stirring occasionally, for 15 minutes.
Add the salmon to the pot. Simmer, covered, until the salmon is just done, about 5 minutes. Remove the cilantro stems. Serve the soup garnished with the cilantro leaves and scallions.
We used long-grain rice for our soup. In China and Japan, it would be made with short-grain, which is starchier and dissolves into the soup more readily. If you want to go the short-grain route, arborio is readily available.