Combine first 5 ingredients in a small bowl, stirring with a whisk.
Coarsely chop bok choy leaves, and arrange on one end of parchment paper cover pan.
Coarsely chop bok choy stems and arrange in a single layer on same pan.
Place salmon, skin side down, in a single layer on top of leafy greens. Pour half of soy sauce mixture evenly over salmon; pour remaining half evenly over bok choy stems.
Broil for 5 minutes; stir stems. Broil an additional 4 minutes or until desired degree of doneness for the salmon.
Arrange bok choy on plate.. Top with salmon fillet and green onions.