Instructions

1. In a medium serving bowl, combine the cilantro, parsley, and mint or dill leaves and tender stems, roughly chopped.
2. Add the sliced scallions, red-pepper flakes (¼ to ½ teaspoon, according to taste), 3 tablespoons lemon juice, and 2 tablespoons olive oil to the bowl.
3. Season the herb mixture with salt and black pepper to taste and toss until the leaves look glossy. Adjust seasoning with more lemon juice or olive oil if needed. Set aside.
4. Preheat the broiler with the rack positioned 6 inches from the heat source.
5. In a small bowl, whisk together 2 tablespoons soy sauce and 1 tablespoon Dijon mustard until smooth.
6. Trim the woody ends from 1 large bunch of asparagus. Spread the asparagus on a large sheet pan and toss with the remaining 1 tablespoon olive oil.
7. Season the asparagus well with salt and black pepper.
8. Move the asparagus to the sides of the sheet pan.
9. Place 4 salmon fillets (4 to 6 ounces each, at least ¾-inch thick), skin side down, in the center of the sheet pan.
10. Season the salmon fillets with salt and black pepper.
11. Brush the tops and sides of the salmon with the soy sauce and mustard mixture.
12. Toss the asparagus in the remaining soy sauce and mustard mixture.
13. Use a paper towel to wipe off any excess soy sauce from the sheet pan to prevent smoking during broiling.
14. Broil the salmon and asparagus until the salmon is opaque with a deep brown crust: about 6 to 8 minutes for medium rare, or 8 to 10 minutes for medium doneness. Adjust time by reducing 1 to 2 minutes for thinner fillets.
15. If the salmon browns too quickly or the pan smokes excessively, move the pan to a lower rack to finish cooking.
16. Serve the salmon and asparagus topped with the herb salad, or serve the herb salad on the side with a final sprinkle of black pepper.