How to Make It
Preheat oven to broil with rack positioned 6 inches from heat source. Whisk together maple syrup, soy sauce, mustard, vinegar, and crushed red pepper in a small bowl.
Line a baking sheet with heavy-duty aluminum foil. Arrange salmon, skin side down, in center of baking sheet; brush evenly with some of the syrup mixture. Place 2 orange pieces on each salmon fillet; brush evenly with some of the syrup mixture. Arrange bok choy, cut side up, around salmon on baking sheet. Brush bok choy evenly with oil and remaining syrup mixture; sprinkle with salt.
Broil in preheated oven until bok choy is tender and charred and salmon is cooked to medium doneness (about 145°F), about 8 minutes. Sprinkle evenly with sesame seeds; serve immediately.