Preheat the oven to 425°F and line a large sheet pan with parchment paper. Spread the halved baby potatoes onto the pan with olive oil, salt, and pepper before roasting them for 10 minutes so they begin softening properly.
Pat the salmon fillets dry and coat them with a mixture of olive oil, lemon juice, garlic, paprika, oregano, salt, and black pepper to build balanced flavor while helping the fish roast evenly.
Remove the sheet pan from the oven and add the broccoli, zucchini, and bell pepper around the potatoes. Place the salmon fillets in the center and top with lemon slices for extra freshness.
Roast everything together for 12–15 minutes until the salmon flakes easily with a fork and the vegetables develop lightly caramelized edges with tender centers.