Season the salmon fillets with salt, black pepper, and red pepper flakes (if using) on both sides. Set aside.
In a small bowl, combine the orange juice, orange zest, minced garlic, and chopped parsley. Mix well and set aside.
Heat the olive oil in a large skillet over medium heat. Once hot, gently place the salmon fillets in the skillet, skin side down. Cook for about 4-5 minutes, depending on the thickness of the fillets.
Carefully flip the salmon fillets and pour the orange sauce over them. Cook for an additional 3-5 minutes, or until the salmon is cooked through and flakes easily with a fork.
Remove the skillet from heat and let the salmon rest for one minute before serving. Drizzle any remaining sauce from the skillet over the salmon.
Serve the salmon with your choice of side dishes, such as steamed vegetables or rice.
For an added touch, you can garnish the salmon with additional fresh parsley and orange slices before serving.