Preheat your grill or grill pan to medium-high heat.
Mince the garlic and finely chop the fresh dill and parsley.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, dill, parsley, sea salt, and black pepper to create a marinade.
Trim the woody ends off the asparagus and toss them with a small amount of the herb marinade until lightly coated.
Brush the remaining herb marinade generously over the top and sides of the salmon fillet.
Place the salmon on the grill, skin-side down first, and cook for about 4-5 minutes without moving it to ensure a good sear.
Add the asparagus to the grill alongside the salmon, turning occasionally.
Flip the salmon carefully and grill for another 3-4 minutes until it reaches your desired doneness and the asparagus is tender-crisp with light char marks.
Remove from heat and serve immediately, garnishing with extra fresh herbs if desired.