Step 1

Heat a wok or large nonstick skillet over high. Add the first five ingredients (through garlic); cook 5 to 7 minutes or until lightly cooked, stirring frequently and adding water, 1 to 2 tablespoons at a time, as needed to prevent sticking.

Step 2

Stir in bok choy and a pinch of Sichuan pepper flakes (if using). Cook and stir about 2 minutes more or until bok choy starts to turn bright green. Add 7 cups water. Bring to boiling.

Step 3

Meanwhile, in a small bowl whisk together a pinch of Sichuan pepper flakes (if using) and the next five ingredients (through lemon juice). Stir mixture into soup. Return to boiling; turn off heat. If desired, sprinkle with cilantro and additional Sichuan pepper flakes.