Begin by prepping the ingredients. Peel and dice the mango into small cubes. Cut the red bell pepper into similarly sized pieces as the mango. Remove the jalapeño stem, devein, and remove the jalapeño seeds before dicing it. Finally, chop the cilantro leaves.
In a large bowl, add all the ingredients, including the diced mango, bell pepper, red onion, chopped cilantro, jalapeño, lime juice, apple cider vinegar, salt, pepper (and garlic, chili powder, cumin, and garlic, if using).
Mix well to ensure that all the ingredients are evenly combined. Gently stir in avocado chunks, if using.
Cover the bowl with plastic wrap and refrigerate for at least 30 minutes or overnight to allow the flavors to meld together.
When you are ready to serve, give the salsa a quick stir, and it is now ready to be enjoyed with your favorite tortilla chips, or make the best taco!