Preheat oven to 425 degrees F. Place the salmon in a parchment paper-lined baking dish, skin-side down. Drizzle with lemon juice and oil; season with salt and pepper. Cover and bake 12-15 minutes, or until cooked through. Uncover and cool to room temperature. Cover and chill in the fridge for at least 2 hours. Whisk the ingredients for the salad, except the cucumber, in a medium bowl. Add the cucumber and gently toss to coat. Divide the salad among plates, top with the salmon, garnish with lemon and dill, and serve.