Cut leafy ends off bok choy, leave small leaves whole and slice larger leaves into bite-size pieces; cut stem ends into slices (keep separate from leaves). Set aside.

In large pot, combine broth, 1/2 cup (125 mL) water, ginger and garlic; cover and bring to boil over medium-high heat. Stir in chicken, mushrooms, carrots and reserved bok choy stems. Reduce heat to medium-low, cover and simmer for 3 minutes.

Meanwhile, in large pot of boiling water, cook noodles according to package directions. Drain and divide among bowls.

Add bean sprouts, vinegar, soy sauce, sriracha and sesame oil to soup pot; return to boil. In small bowl, stir cornstarch with 2 tbsp (25 mL) of cold water until smooth. Stir into pot and simmer until slightly thickened, about 2 minutes, reducing heat if necessary.

In measuring cup, whisk egg; slowly pour in a thin stream around the edge of the pot and stir once or twice to form fine egg threads. Stir in reserved bok choy leaves. Ladle soup over noodles.

TIPS:

One boneless, skinless Ontario Chicken Breast can be substituted for the thighs.

If using shiitake mushrooms be sure to remove and discard stems, slice only caps.