Rinse the jasmine rice thoroughly under cold water until the water runs clear to remove excess starch.
In a medium heavy-bottomed pot, combine the rinsed rice, chicken bone broth, minced ginger, and minced garlic.
Bring the liquid to a boil, then immediately reduce the heat to low, cover the pot, and simmer for 30 to 40 minutes.
While the rice simmers, thinly slice the chicken breast into bite-sized strips and slice the shiitake mushrooms.
Stir the congee occasionally to ensure the rice breaks down and doesn't stick to the bottom of the pot.
Add the sliced chicken, mushrooms, and tamari to the pot during the last 15 minutes of cooking, stirring well.
Once the rice has reached a thick, silky consistency, season the porridge with sea salt and white pepper.
Ladle the congee into a bowl and garnish with a drizzle of toasted sesame oil and freshly sliced scallions.