Wash the rice. Place the rice in a bowl, add water and swish around. Drain the cloudy water. Repeat until the water runs clear. Drain the remaining water and set the rice aside.
Heat a pot over high heat with a little vegetable oil. Add a teaspoon of garlic, a teaspoon of ginger, and a tablespoon of chopped scallion, white and light green parts only. Let them sizzle for a few seconds before adding the mushrooms. Reduce the heat to medium high and let the mushrooms cook until soft; about 5 minutes. Stir occasionally.
Add an additional teaspoon of garlic, a teaspoon of ginger, a tablespoon of scallions (again only white and light green parts), 3 cups of broth, and cooked beans. Turn the heat to high, let the broth come to a boil, then simmer on low for about 3 minutes.
Turn the heat off. Remove the beans and mushrooms with a slotted spoon and transfer to a bowl to cool. Optionally, chill the beans and mushrooms in the fridge as the main protein in this dish is traditionally served cold over hot rice.
You will have about 3 cups of broth remaining. Reserve one cup and set aside, checking that you have 2 cups left in the pot. Add the washed rice to the pot and turn the heat to high. When it comes to a boil, turn the heat to low, cover and simmer until the rice has absorbed all the broth; about 15 minutes. Do not stir the rice while simmering!
Serve the hot rice with beans and mushrooms on top, along with Scallion Ginger Sauce, Hainan Chili Sauce, sliced cucumber, carrots, the chopped scallion (the dark green parts), cilantro, and the remaining broth.