In a medium size pot, bring the chicken broth and 1/2 teaspoon salt to a boil. Add the couscous and reduce the heat. Cover and cook until the couscous is tender, approximately 10 minutes.
Drain the couscous. Drizzle with olive oil and mix to prevent it from sticking together. Set aside.
Prepare the salmon while the couscous is cooking. Season the salmon with salt and pepper. Drizzle 2 teaspoons of the lemon dill dressing on each piece of salmon. Spread it around to cover the top.
Grill the salmon until firm. Flake the salmon into large chunks using a fork. Drizzle the flaked salmon with 2 tablespoons of the lemon dill dressing.
Assemble the salad by combining the arugula and the couscous in a large bowl. Drizzle it with 2 more tablespoons of the dressing.
Pour the mixture into a large serving dish. Top it with the flaked salmon, tomatoes, and the feta cheese.
Garnish with the fresh dill and serve.