Preheat and prep: Set your oven to 425°F (220°C). High heat gives sweet potatoes a chance to caramelize — browning develops flavor through the Maillard reaction. Line a baking sheet with parchment or a foil-lined rack to encourage even air circulation and easy cleanup.

Cut the sweet potatoes into uniform 1/2-inch cubes. Uniform pieces roast evenly; smaller pieces will crisp faster. Toss the cubes with 1 tbsp (15 ml) olive oil, 1/2 tsp kosher salt and a pinch of black pepper. Spread them in a single layer on one side of the baking sheet — overcrowding traps steam and prevents browning.

Roast the sweet potatoes for 20 minutes, flipping once halfway through. Start them first because they need the longest time in the oven. Flip to expose new surfaces to heat — this encourages even caramelization and crisp edges.

Bring the salmon to room temperature for 5–10 minutes while the potatoes begin roasting. Pat the fillets very dry with paper towels — removing surface moisture helps the exterior develop a light crust rather than steaming. Season both sides with the remaining 1/2 tsp kosher salt and 1/4 tsp black pepper.

Make the lemon-garlic-herb coating: In a small bowl combine 1 tbsp olive oil (15 ml), the minced garlic, the zest of half the lemon, and 1 tbsp chopped dill (or parsley). Spoon or brush this over the top of each salmon fillet. The oil and acid from lemon zest carry aromatic compounds and help deliver bright flavor across the fillet.

When the sweet potatoes have about 8–10 minutes left, place the salmon (skin-side down) on a separate lightly oiled baking sheet or on the empty side of the sheet if there’s space. Slide the salmon into the oven and roast at 425°F for 10–12 minutes for a fillet ~1-inch (2.5 cm) thick. High oven heat gives a short, gentle burst of cooking that sets the exterior while keeping the interior moist. Aim for an internal temperature of 125–130°F (52–54°C) for medium-rare, or up to 145°F (63°C) if you prefer it fully cooked (USDA recommends 145°F).

Steam the broccoli while the salmon finishes: Bring 1–2 inches (2.5–5 cm) of water to a simmer in a saucepan fitted with a steamer basket or use a microwave-safe bowl. Steam the broccoli for 4–6 minutes until bright green and tender-crisp. Steaming preserves color and nutrients; avoid overcooking or it becomes mushy and dull in flavor. If you like, plunge briefly into ice water (shock) to lock in color, then drain.

Finish and rest the salmon: Remove the salmon from the oven when it flakes easily but still looks slightly translucent in the center. Rest the fillets 3–4 minutes — residual heat will carry them to final doneness and letting them rest keeps juices from spilling out when you cut into them.

Optional lemon-herb butter (recommended): In a small skillet, melt 1 tbsp butter over low heat, stir in a teaspoon lemon juice and the remaining 1 tbsp chopped herbs. Spoon over the salmon and roasted sweet potatoes for a glossy finish and an additional layer of flavor (butter is optional — olive oil also works).

Plate: Divide sweet potatoes and broccoli between two plates. Place a salmon fillet on top of the potatoes, drizzle with the lemon-herb butter or a squeeze of fresh lemon, and garnish with a small sprig of dill and a lemon wedge. Serve immediately.