Heat oven to 425 degrees F.
Line a rimmed baking sheet with aluminum foil and spray with cooking spray.
Spread sweet potatoes and broccoli onto prepared pan and drizzle with 2 tablespoons of olive oil, or more as needed to fully coat the vegetables. Toss the vegetables in the oil and season with salt and pepper, to taste.
Roast for 10-15 minutes, or until potatoes are just about fork-tender.
While potatoes and broccoli are roasting, prepare glaze for salmon. In a small bowl, whisk together maple syrup, mustard, ¼ teaspoon salt, and ¼ teaspoon pepper.
Remove vegetables from oven and turn oven setting to BROIL on “high.” Spread broccoli and potatoes to outer edges of sheet pan to make room in the center for the fish.
Place salmon in center of tray, leaving at least ½-inch of space in between each fillet so that they cook evenly. Brush glaze on top of each piece of salmon.
Broil for 7-10 minutes, or until salmon flakes easily with a fork and top is browned and crispy. Potatoes and broccoli should be roasted and tender as well. The total broiling time will depend on the size and thickness of your fish.