Pat the salmon fillet completely dry with paper towels to ensure a crispy sear, then season both sides with sea salt, black pepper, and garlic powder.
In a small mixing bowl, whisk together the Greek yogurt, chopped fresh dill, lemon juice, and lemon zest until the sauce is smooth and creamy.
Heat the olive oil in a non-stick or cast-iron skillet over medium-high heat until shimmering.
Place the salmon in the skillet, skin-side down, and sear for 4-5 minutes without moving it to develop a golden crust.
Carefully flip the salmon and cook for an additional 3-4 minutes, or until the internal temperature reaches 145 degrees Fahrenheit and the fish flakes easily.
While the salmon finishes, steam or sauté the asparagus spears in a separate pan for 3-5 minutes until they are bright green and tender-crisp.
Transfer the salmon and asparagus to a plate and top the fish with the prepared lemon-dill sauce before serving.