Pre-heat oven to 375°F and line a large, rimmed baking sheet with a piece of parchment paper or a Silpat® baking mat. Place salmon fillets on the prepared baking sheet and generously season with salt and black pepper, to taste. Set aside.
In a small bowl, whisk together 2 tablespoons of olive oil with 3 tablespoons lemon juice. Add the mustard, honey, and garlic and whisk to combine. Brush each fillet with the honey-mustard mixture until coated.
Add chopped pistachios and ground cardamom to a small bowl and stir to combine. Evenly divide the pistachio mixture among the salmon fillets, gently pressing the mixture into each fillet to ensure it adheres.
Place the cherry tomatoes in a medium bowl and drizzle with one tablespoon olive oil. Season with salt and black pepper, to taste, and toss to combine. Arrange the seasoned tomatoes around the salmon fillets and place in the pre-heated oven to roast until the salmon is flakey and the cherry tomatoes are blistered approximately 13-15 minutes.
Meanwhile, combine the mixed salad leaves, cucumber, red onion, and Kalamata olives in a large bowl. Drizzle with the remaining olive oil and lemon juice and season with salt and black pepper, to taste, and toss to combine. Set aside.
Once baking time is complete, remove salmon and tomatoes from the oven. Serve immediately with the fresh salad on the side. Enjoy!