Roast the Foundation Vegetables: Preheat your oven to 425°F (220°C). In a large bowl, combine the sweet potato cubes, bell pepper strips, and sliced shallot. Drizzle with 2 tablespoons of extra virgin olive oil, the dried oregano, ¼ teaspoon of black pepper, and ⅛ teaspoon of sea salt. Toss thoroughly to ensure everything is evenly coated. Spread the vegetables in a single layer on the large rimmed baking sheet. Roast for 20 minutes, tossing once halfway through.
Prepare the Salmon: While the vegetables are roasting, prepare the salmon. In a small bowl, combine the remaining 2 tablespoons of extra virgin olive oil, the minced garlic, and the zest of both lemons. Pat the salmon fillets completely dry with a paper towel, then sprinkle them with the remaining ⅛ teaspoon of sea salt and ¼ teaspoon of black pepper. Brush the garlic-zest oil mixture evenly over the top of each fillet.
Add Remaining Vegetables: After 20 minutes, remove the baking sheet from the oven. The sweet potatoes should be starting to soften. Add the cherry tomatoes and drained artichoke hearts to the pan, gently tossing them with the other vegetables directly on the sheet.
Cook the Salmon: Create six small clearings among the vegetables on the baking sheet. Nestle a salmon fillet into each space. Return the pan to the oven and roast for an additional 12-15 minutes, or until the salmon is opaque and flakes easily with a fork and the vegetables are tender and lightly caramelized.
Add Fresh Elements: Remove the sheet pan from the oven. Immediately sprinkle the entire pan with the chopped fresh parsley and the oil-cured olives. The residual heat will gently warm them and release their aromas.
Finish and Serve: Just before serving, squeeze the fresh juice of one lemon over the entire pan of salmon and vegetables. Serve immediately, portioning one salmon fillet and a generous helping of the roasted vegetable medley onto each plate.