Preheat and prep. Preheat oven to 425°F (220°C). Line a rimmed baking sheet with parchment or lightly oil it. Preheating to a high temperature lets the sweet potatoes roast and the salmon finish quickly so the crust browns without overcooking the fish.

Cut and season sweet potatoes. Peel (optional) and cut the sweet potatoes into 1/2-inch cubes or 3/4-inch wedges for even roasting. Toss the pieces with 1 tbsp olive oil, 1/2 tsp salt and 1/4 tsp black pepper. Spread them in a single layer on one side of the prepared baking sheet, leaving space for the salmon later. Cutting into uniform pieces ensures even caramelization; a single layer prevents steaming and gives better browning.

Start roasting sweet potatoes. Put the tray with sweet potatoes in the hot oven and roast for 15 minutes uncovered. Starting the roots first gives them time to soften and develop color before the salmon goes in, since salmon cooks quickly.

Make the herb-panko crust. While the sweet potatoes begin roasting, combine 1/4 cup panko breadcrumbs, 2 tbsp chopped parsley, 1 tsp lemon zest, 1 tbsp olive oil, 1 minced garlic clove, and a pinch (about 1/4 tsp) of salt and a few grinds of pepper in a small bowl. Toss until the oil evenly coats the crumbs and the mixture clumps slightly. Coating the crumbs in oil helps them brown in the oven and adhere to the fish; the lemon zest brightens the crust so the fat of the salmon doesn't taste heavy.

Pat and season the salmon. While the crumbs rest for 2–3 minutes to soak up the oil, pat the salmon dry with paper towels (dry surface = better crust adhesion). Lightly season both sides with salt (about 1/4 tsp total per fillet) and a few grinds of pepper. If skin-on, dry the skin well to encourage crisping. Drying the fish reduces steaming and helps the crust stick and brown.

Apply the crust and arrange on sheet. Press the panko mixture onto the top (skinless side) of each fillet in an even layer, using the flat of your fingers to compact it gently — about 1–2 tablespoons of crust per fillet depending on size. Place the fillets on the baking sheet next to the partially roasted sweet potatoes. Pressing forms contact so the crust won't fall off during baking.

Finish roasting salmon and sweet potatoes. Return the baking sheet to the oven and roast everything for 8–12 minutes, depending on fillet thickness: aim for internal salmon temperature of 125–130°F (52–54°C) for medium-rare to medium (the crust will be golden). Thicker fillets (1 in / 2.5 cm) may need 12 minutes; thinner ones 8 minutes. The hot oven browns the panko while cooking the salmon quickly so it stays moist — use a thermometer or the fork test (salmon flakes when gently pressed but still slightly translucent inside).

Steam the broccoli. While the salmon roasts, bring 1–2 inches (2–3 cm) of water to a simmer in a medium saucepan fitted with a steamer basket (or a small pot). Add the broccoli florets, cover, and steam for 3–5 minutes until bright green and just tender-crisp. Immediate steaming preserves the broccoli's color, nutrients and crisp bite so it balances the softer salmon and potatoes.

Rest the fish briefly. Remove salmon from the oven when it reaches the desired doneness, transfer to a plate and let it rest for 2 minutes. Resting allows residual heat to finish cooking evenly and helps juices redistribute; the crust will set slightly during this time for easier slicing/serving.

Finish and plate. Check potatoes for tenderness and additional browning; if needed, return them to the oven for 2–5 more minutes. Serve each salmon fillet with half the roasted sweet potatoes and half the steamed broccoli, squeezing a lemon wedge over the crusted salmon to brighten flavors. Season vegetables to taste with a pinch of salt and a drizzle of olive oil if desired.

Optional finishing touch. For extra gloss and flavor, brush a very light smear (about 1/2 tsp) of melted butter or additional olive oil over the panko crusted top immediately after baking; this deepens color and adds richness. Use sparingly to avoid soggy crumbs.