Season salmon fillets with 1 teaspoon sea salt and ½ teaspoon black pepper.
For the chimichurri sauce, add the parsley, garlic cloves, oregano, olive oil, vinegar, 1 teaspoon sea salt, ¼ teaspoon black pepper, and the red pepper flakes to a food processor.
Pulse until well combined but still slightly chunky.
Place salmon fillets, skin-side down, on a parchment-lined baking sheet.
Generously spoon the chimichurri sauce over the salmon fillets, coating the tops and sides.
Bake for 12-15 minutes, or until salmon is opaque and flakes easily with a fork.
Divide salmon into 4 individual servings and transfer to plates.
Garnish the salmon with lemon slices and fresh parsley sprigs; serve with additional chimichurri on the side.