01 - In a medium bowl, combine mango, red onion, red bell pepper, jalapeño, cilantro, and lime juice. Season with salt and pepper to taste. Mix gently, cover, and refrigerate until ready to serve.
02 - Pat the salmon fillets dry with paper towels. Brush both sides with olive oil.
03 - In a small bowl, mix Cajun seasoning, salt, and black pepper. Generously coat both sides of each salmon fillet with the seasoning.
04 - Heat a large cast-iron skillet or heavy-bottomed pan over medium-high heat until very hot.
05 - Place the salmon fillets in the skillet, skin-side down if applicable. Cook for 3-4 minutes without moving, until a dark crust forms.
06 - Carefully flip the fillets and cook for another 2-4 minutes, until the salmon is cooked to your desired doneness (internal temperature should reach 145°F).
07 - Remove the salmon from the pan and let rest for 2 minutes.
08 - Serve each salmon fillet topped generously with mango salsa.