Melt the butter in a medium saucepan over medium heat.
Add the dry orzo and toast, stirring frequently, for 2–3 minutes until lightly fragrant.
Pour in the stock and add a pinch of kosher salt and pepper, then bring to a boil.
Reduce heat to a simmer, cover, and cook 12–15 minutes, stirring once or twice, until the liquid is absorbed and orzo is tender.
Remove from heat and stir in the Parmesan, lemon juice, and lemon zest until creamy; adjust seasoning to taste.
In a small bowl, combine dried parsley, dried minced garlic, garlic powder, crushed red pepper, 1/2 teaspoon salt, and 1/2 teaspoon pepper to make the salmon seasoning.
Pat salmon filets dry with paper towels and season both sides with the prepared seasoning.
Heat 1–2 tablespoons olive oil in a cast-iron or nonstick skillet over medium heat until shimmering.
Add the salmon, sear skin-side up or presentation side down for 2–3 minutes, then gently flip and cook 3–5 minutes more until opaque and cooked through.
Serve the salmon over the lemon Parmesan orzo and garnish with chopped fresh parsley.