Broiled Salmon With Vegetables and Scallion Rice

Name: Broiled Salmon With Vegetables and Scallion Rice
Ingredients: 4 skin-on salmon fillets (each 5 ounces), preferably wild Alaskan; Kosher salt and freshly ground pepper; 3 tablespoons reduced-sodium soy sauce; 2 tablespoons light-brown sugar; 2 tablespoons unseasoned rice vinegar, plus more for rice; 2 bell peppers, cut lengthwise into 1 ½-inch-thick strips; 1 bunch thick asparagus (12 ounces), trimmed; 8 ounces cremini or button mushrooms, halved; 1 bunch scallions (about 8), trimmed; 3 tablespoons vegetable oil, such as safflower; Cooked rice and toasted sesame seeds, for serving