Cook the quinoa according to package directions. When the quinoa is cooked, let it cool for a few minutes. Add the sesame oil and most of the sliced scallions, leaving some for garnish. Cover and set aside.
In a measuring cup, whisk the soy sauce, mirin, garlic, ginger and honey.
In a small bowl, add the salmon pieces and pour half of the marinade over the salmon. Turning to coat all pieces. Let the salmon marinate at room temperature for 15 minutes.
Heat a large nonstick or enamel-coated cast iron skillet over medium-high heat.
Add 2 tablespoons vegetable oil. Add the Bok choy and cook until the leaves start wilting, 2 to 3 minutes.
Add the mushrooms and about two tablespoons of the reserved marinade over the mushrooms. Add the lemon zest and cook until soft, about 1 minute.
Using a slotted spoon, remove the cooked vegetables, place them in a bowl, and set aside.
Turn the heat on high and let the liquid in the pan mostly evaporate for about 1 minute.
Lower the heat to medium-high and add the remaining 1 tablespoon vegetable oil.
Add the salmon pieces to the skillet along with all the marinade in which the salmon was marinating.
Cook until the salmon is golden brown and cooked through, 3 minutes per side.
Remove the cooked salmon and set aside.
With the remaining marinade in the measuring cup, add it to the hot skillet and cook for about 1 minute. The marinade will slightly thicken. Once it has thickened slightly, remove it from heat. This sauce will be used to top each bowl.