Peel and cut mango away from the pits

Cut mangos into large dice and place in a large bowl

Dice red onion to make 3/4 cup

Remove cilantro leaves from stems and mince

Add onion and cilantro to mango. Cut stems off serrano chili and slice across into thin slices

Peel garlic and mince and add to mangos along with chili

Toss in black beans, lime juice, olive oil and sugar

Let stand at least 30 minutes or refrigerate up to 3 hours before serving.