In a small bowl combine all the ingredients except the salmon. Coat the salmon fillets evenly on both sides with the spice mixture, pressing the mixture in so it sticks.
Heat the oil in a large heavy preferably nonstick skillet over high heat. Add the salmon and cook until blackened on one side, about 4 minutes. Carefully turn the fillets and continue cooking until the other side is blackened and the salmon is tender, flaky, but not overcooked, about another 4 minutes.
For the dressing:
Combine all the dressing ingredients in a blender and blend until smooth. Season to taste with salt and pepper. Press plastic wrap against the surface of the dressing and refrigerate until ready to use.
To assemble:
In a large bowl combine the salad greens, tomatoes, and cucumber. Divide the mixture among four serving bowls and top each with a salmon fillet. Drizzle with dressing. Serve.
Notes
For best results, use wild-caught Copper River Alaskan salmon or other high quality salmon.