Put water and bouillon cubes in a large pot. Bring to boil. (If you're not about bouillon cubes, you can easily swap for 8 cups of vegetable or chicken or beef stock and then omit water. You can learn how to make your own vegetable stock from scraps here)
While the stock is coming to a boil, cut the scallions, separating the white and green parts. For the white part, cut in half lengthwise, whereas for the green parts, thinly slice as this will be for plating!
Once stock is at a boil, bring down to a simmer and add the white parts of the scallions, the ginger, and 1 TSP. salt. If you are using stock from the store, make sure to taste it before adding salt, they sometimes can be quite high in sodium.
Put the lid on and simmer the stock for 15-minutes.
While stock is simmering, cook noodles according to directions on packaging.
Once noodles are cooked through, drain and rinse with cold water to stop them from cooking further.
Place noodles in the bottom of your soup bowl.
Add bok choy to your broth and stir gently. Continue to simmer for 2-3 minutes, just until the bok choy becomes a bright green.
Ladle your broth and bok choy over the noodles.
Top the Ginger-Scallion Broth with Noodles with cilantro, squeeze a lime over, and enjoy!