Grate Parmesan cheese, finely chop onion, and mince garlic cloves. Pat salmon fillets dry with paper towels and season both sides with garlic powder, sweet paprika, and 1/2 teaspoon each salt and pepper.

Heat oil and butter over medium-high heat in large nonstick skillet. Add salmon fillets and sear 3-4 minutes per side. Remove from skillet and set aside.

Reduce heat to medium, add garlic and onion. Cook until soft and fragrant, about 2 minutes. Stir in thyme and remaining salt and pepper. Add orzo and toast for 1 minute.

Pour in broth and bring to a boil. Reduce heat to medium-low to maintain a simmer. Cook uncovered, stirring occasionally, until orzo is almost al dente and most liquid is absorbed, about 8 minutes.

Add spinach, stir and simmer until wilted, about 2 minutes. Stir in lemon juice and Parmesan. Add more broth if needed. Taste and adjust salt.

Return salmon to skillet and simmer 2-3 minutes, or until salmon is heated through. Top with freshly ground black pepper and chili flakes before serving.