Season salmon with cumin; sear fillets in a skillet over medium high heat; finish cooking in oven until internal temperature reaches 135 degrees F.
Make dressing: combine broth and next ten ingredients (ginger through garlic); bring to a rapid boil stirring constantly; remove from heat and keep warm.
Divide greens, mushrooms, cucumbers and tomatoes evenly among 6 serving plates; top each with a salmon fillet.