Make salad dressing first.
Mix lime juice, olive oil, maple syrup, chili powder and sea salt in a small bowl. Taste and adjust seasonings as you wish. Set aside until needed.
Peel and dice both the mango and avocado into one inch cubes. Discard the pits.
Put it in a salad bowl with the red onion and add lime dressing on top.
Gently toss everything without mashing the avocado. Sprinkle with fresh cilantro leaves and serve directly.