Preheat your grill or grill pan to medium-high heat.
In a small bowl, whisk together the plain Greek yogurt, lemon juice, half of the fresh dill, half of the fresh parsley, and a pinch of salt and pepper to create a creamy herb sauce.
Mince the garlic clove and combine it with the remaining dill, parsley, and lemon zest.
Pat the salmon fillet dry and rub the herb-zest mixture over the top, pressing gently to adhere.
Toss the asparagus spears with the extra virgin olive oil and the remaining sea salt and black pepper.
Place the salmon on the grill, skin-side down, and cook for 4-5 minutes until the skin is crispy.
Add the asparagus to the grill alongside the salmon, turning occasionally.
Flip the salmon carefully and grill for another 3-4 minutes until the fish is opaque and the asparagus is tender with light char marks.
Remove from the heat and serve the salmon and asparagus immediately with a generous dollop of the lemon-herb yogurt sauce.