How to Make It
Preheat oven to 375°F. Line a quarter sheet pan with parchment paper. Whisk together hoisin sauce, lime juice, 1 1/2 tablespoons oil, ginger, garlic, and cayenne in a small bowl; set aside.
Toss together brussels sprouts, bell pepper, onion, 1/4 teaspoon salt, and remaining 1 1/2 tablespoons oil. Place salmon on prepared sheet pan. Arrange vegetable mixture around salmon. Drizzle 1/3 cup hoisin mixture on salmon and vegetable mixture; reserve remaining hoisin mixture. Sprinkle salmon with sesame seeds.
Bake until salmon is cooked to desired degree of doneness and vegetables are tender, 16 to 20 minutes. Drizzle 2 tablespoons reserved hoisin mixture over salmon and vegetables, and sprinkle salmon with remaining 1/4 teaspoon salt. Serve with remaining hoisin mixture.