Prep first: Grate Parmesan, chop the onion, and mince the garlic. Pat salmon fillets dry, then season both sides with garlic powder, paprika, and ½ teaspoon each of salt and pepper.
Heat oil and butter in a large skillet over medium-high heat. Sear salmon fillets for 3-4 minutes per side until golden and cooked to preferred doneness. Remove and set aside.
Lower heat to medium and sauté garlic and onion for 2 minutes until fragrant and softened.
Stir in thyme and the remaining salt and pepper. Add orzo and toast for 1 minute.
Pour in broth and bring to a gentle boil. Reduce heat to medium-low and simmer, stirring occasionally, for 8 minutes or until orzo is almost al dente with most liquid absorbed.
Stir spinach into the orzo and cook for 2 minutes until wilted.
Mix in fresh lemon juice and Parmesan cheese. If needed, add a splash of broth to keep the orzo creamy. Taste and adjust seasoning.
Return salmon to the skillet and simmer for 2-3 minutes to rewarm.
Top with freshly ground black pepper and chili flakes before serving.