Wash and quarter the tomatoes. Wash and clean spring onions and cut into fine rings. Peel the mango, cut the flesh from the stone and chop it into small pieces.
Rinse fish and pat dry. Heat the oil in a large pan. Fry the fish for 4-5 minutes at medium heat, turn with the help of two spatulas and fry for another 4-5 minutes. Season lime, salt and pepper with juice from 1⁄2.
In the meantime, halve the avocado, remove the core, remove the flesh from the skin and cut into small cubes. Mix with tomatoes, spring onions and mango. Season with salt, pepper and the rest of the lime juice. Serve the fish with salsa and sprinkle with coarse pepper to taste. Serve with baguette.