In a small bowl, whisk the low-sodium chicken broth with the soy sauce, mirin, and cornstarch slurry.

Heat a nonstick wok or large, deep skillet until very hot, about 3 minutes. Add the canola oil, julienned ginger, garlic, and crushed red pepper and stir-fry until fragrant, about 20 seconds. Add the onion and shiitake slices and stir-fry until they are lightly browned and nearly tender, about 3 minutes. Add the sliced bok choy and cook until the leaves are wilted and the stems are crisp-tender, about 2 minutes. Add the shrimp and stir-fry until they are pink and curled and nearly cooked through, about 3 minutes.

Stir the sauce, then stir it into the wok and cook until it is slightly thickened, about 2 minutes. Transfer the shrimp-and-bok choy stir-fry to a medium serving bowl and garnish with the crispy noodles. Serve the stir-fry with brown rice.