Prepare the Oven and Vegetables: Position an oven rack in the center and preheat to 400°F (200°C). In a large mixing bowl, combine the halved potatoes, sliced bell peppers, and grape tomatoes. Drizzle with 1½ tablespoons of the olive oil. Add the sliced garlic, black pepper, salt-free Greek seasoning, smoked paprika, and kosher salt. Toss thoroughly until everything is evenly coated.
Roast the Vegetables: Spread the vegetable mixture in a single, even layer on a large, heavy-duty sheet pan. Transfer to the preheated oven and roast for 25 minutes to allow the potatoes and peppers to begin softening.
Season the Salmon: While the vegetables are roasting, pat the salmon fillets completely dry with a paper towel. Arrange them on a plate and drizzle with the remaining 1 tablespoon of olive oil, using your fingers to gently coat all sides.
Combine and Cook: After 25 minutes, carefully remove the pan from the oven. Gently nudge the vegetables to create spaces for the salmon fillets. Place the seasoned salmon on the pan among the vegetables. Return the pan to the oven and bake for another 12 to 15 minutes.
Check for Doneness: The meal is ready when the potatoes are fork-tender and the salmon is opaque and flakes easily with a fork. For best results, the internal temperature of the salmon should register 140°F (60°C) in the thickest part.
Add Fresh Finishings: Remove the sheet pan from the oven. Zest one of the lemons directly over the entire pan. In a small bowl, combine the chopped fresh parsley, mint, dill, and the rinsed Kalamata olives. Sprinkle this vibrant herb mixture evenly over the salmon and vegetables. Finally, cut both lemons in half and squeeze the juice from two halves over the dish. Serve immediately with the remaining lemon wedges on the side for squeezing.