Wash all produce. Dice the mango and cucumber into bite-sized pieces, and slice the red onion thinly. Chop cilantro finely and set aside.

In a separate bowl, combine lime juice, fish sauce, honey, and chili flakes. Whisk until well combined.

Add the diced mango, cucumber, red bell pepper, and red onion to the bowl with the dressing. Gently fold to combine.

Let the salad rest for about 10 minutes at room temperature to allow flavors to meld.

Serve the salad in a bowl, garnished with extra cilantro if desired.