- 1 pound Brussels sprouts, trimmed and halved
- 1 large red onion, cut into 1-inch wedges, stem ends left intact
- 2 tablespoons olive oil
- kosher salt and black pepper
- 2 tablespoons pure maple syrup
- 2 tablespoons whole-grain mustard
- 1 1/2 pounds skinless salmon fillet, cut into 4 pieces
- lemon wedges, for serving
- Heat oven to 450° F, with the racks in the upper and lower thirds. On a rimmed baking sheet, toss the Brussels sprouts and onion with the oil, ½ teaspoon salt, and ¼ teaspoon pepper. Roast on the bottom rack, tossing once, until golden and tender, 15 to 20 minutes.
- Meanwhile, in a small bowl, mix together the maple syrup, mustard, and ¼ teaspoon each salt and pepper. After the vegetables have cooked for 12 minutes, place the salmon on a second rimmed baking sheet and brush it with the maple mixture. Roast on the top rack until opaque throughout, 6 to 8 minutes.
- Serve the salmon with the vegetables and lemon wedges.