Add the water to a large pot over high heat. Add the whole grouse, the ginger, scallion, onion, garlic, and dried mushrooms. Bring to a strong simmer, then lower to a medium simmer. Cook for 30-40 minutes uncovered, or until grouse is fully cooked. Pick out grouse and mushrooms and set aside to cool. Discard the rest of the aromatics by straining the liquid into a large bowl – reserve the liquid.
Add 1 tablespoon of sesame oil to the pot and put back over medium heat. Add the rice, carrots, and celery and sauté for a few minutes, or until rice turns opaque. Add 6 cups of the reserved stock back in (top up with water if you don’t have enough). Bring to a simmer and cook for 20-30 minutes, or until rice is soft and beginning to fall apart. Stir often and reduce heat as needed. Skim off any scum that rises to the surface.
Meanwhile, chop the mushrooms and set aside. Pull all of the meat from the grouse and discard the bones. Toss the meat with the 1 teaspoon sesame oil, the salt, pepper, and garlic. Set aside.
Once the rice is to your liking (add more water if you prefer a soupier rice porridge), add the grouse and mushrooms and cook for 1-2 minutes. Taste for salt. Serve garnished with sliced scallions and sesame seeds and with a side of kimchi. Enjoy!