Preheat your oven or grill to medium-high heat. Place the salmon fillets under the grill for 10-12 minutes until cooked through and lightly crispy.
Boil your chosen pasta according to package instructions until al dente. Three minutes before the pasta is done, toss in asparagus to blanch it lightly. Drain well and let it cool slightly.
While the pasta is cooking, chop your romaine, spinach, tomatoes, and herbs. If using sun-dried tomatoes, roughly chop them to balance the flavors in each bite.
Whisk together olive oil, balsamic vinegar, Dijon mustard, and lemon zest in a small bowl. Taste and adjust seasoning with salt and pepper. The dressing should be bright, tangy, and complement the salmon without overpowering it.
In a large bowl, mix the cooked pasta, asparagus, chopped vegetables, and flaked salmon. Pour the dressing over the top and toss gently until everything is coated. Serve immediately or chill for later.