Use a sharp knife to cut around the mango pit, then peel away the skin carefully, revealing the juicy flesh. Keep your grip steady to avoid slips as the flesh is slippery.
Slice the mango into small cubes or chunks, maintaining a vibrant, juicy appearance. Place the chunks into a mixing bowl.
Add the finely diced red onion to the bowl, watching for its sharp, pungent aroma as it mingles with the mango.
Squeeze fresh lime juice over the mixture, allowing it to brighten the flavors and help meld the ingredients together.
Chop the cilantro finely and sprinkle it into the bowl, adding a fresh, grassy note to the salsa.
Finely dice the jalapeño, removing seeds if you prefer less heat, then stir it into the mixture for a smoky, spicy crunch.
Add a pinch of salt to taste, stirring gently to balance the sweetness of the mango and tartness of the lime.
If desired, drizzle a tablespoon of olive oil over the salsa for added sheen and richness, then give everything a gentle stir.
Let the salsa sit for about 5 minutes to allow flavors to meld and the onion to soften slightly, then give it a final gentle stir.
Serve the mango salsa in a bowl, garnished with extra cilantro if desired, and enjoy immediately for the best freshness and juiciness.