01 -
Preheat the broiler and set a rack 2 inches from the heat. On a large sheet tray lined with aluminum foil, toss the broccoli with the olive oil and a large pinch of salt and pepper. Spread the broccoli out into a single layer. Broil the broccoli while you prepare the salmon.
02 -
Thinly slice the scallions and finely grate the lemon zest. Add both to a small bowl with the mayonnaise, Dijon mustard, and a pinch of salt and pepper. Whisk to combine.
03 -
Remove the broccoli from the oven. Stir the broccoli with a spatula and move it to the outer edges of the baking sheet. Sprinkle each salmon fillet with salt and pepper and place them in the center of the baking sheet. Divide the mayonnaise mixture on top of the fillets, spreading to cover.
04 -
Broil the salmon and broccoli, rotating the pan halfway through, until the sauce on the salmon is deep golden brown and the fillets are opaque, about 5 minutes. Meanwhile, cut half of the zested lemon into wedges.
05 -
Divide the salmon, broccoli, and lemon wedges among 4 plates and serve immediately.