Preheat your oven to 200°C or heat a non-stick skillet over medium-high heat.
Rub salmon fillets with olive oil, salt, and pepper.
If baking, place salmon on a baking sheet lined with parchment paper and bake for 12-15 minutes, or until flaky. If pan-frying, cook salmon in the skillet for 4-5 minutes per side until golden and cooked through.
While the salmon cooks, combine the diced avocado, mango, red onion, capsicum, lime juice, and coriander in a bowl. Season with a pinch of salt and pepper.
Serve the cooked salmon topped with the avocado-mango salsa.