How to Make It
Place a rimmed baking sheet in oven. Preheat broiler to high (keep pan in oven as it preheats).
Combine honey, mustard, vinegar, 3/4 teaspoon pepper, and 1/4 teaspoon salt in a microwave-safe bowl. Microwave at HIGH for 2 minutes, stirring after 1 minute. Reserve 2 tablespoons honey mixture.
Carefully remove pan from oven. Coat pan with cooking spray. Arrange fillets, skin side down, on pan; broil 6 minutes. Brush remaining 2 1/2 tablespoons honey mixture over fillets; broil 2 minutes. Remove pan from oven; brush fillets with reserved 2 tablespoons honey mixture. Keep warm.
Heat 1 tablespoon oil in a large skillet over high. Add half of shallots; cook 1 minute, stirring frequently. Add half of zucchini; cook 3 minutes, stirring occasionally. Place zucchini mixture in a bowl. Repeat procedure with remaining 1 tablespoon oil, remaining shallots, and remaining zucchini. Add remaining 1/4 teaspoon pepper, remaining 1/4 teaspoon salt, and cilantro to zucchini mixture; toss. Serve zucchini with salmon fillets.