Boil a few cups of water. Place the corn in a bowl with the red onions. Add the boiling water, sit for a few seconds and then strain. The corn will be just barely cooked or defrosted and the red onions will be less potent in flavor.
To cube the mango:
Cut on either side of the long pit in the mango, set aside the round halves. Slice off the skin around the pit. Carefully, cut off the flesh around the pit and cut into small chunks. Holding the round half in your hand, slice gently into the fruit until you barely touch the skin on the other side. Alternate the slices to create small cubes. Turn the mango inside out and push or slice off the pieces away from the skin. Repeat this method with the other half.
To cut the avocado:
Slice around the pit to open it up. Remove the pit, either by whacking it with a knife and pulling it out or by squeezing it out. Hold the half in your hand and slice into chunks (similar to the mango method). Scoop out the flesh. Repeat with the other half.
Drain and rinse the black beans.
Toss all of the chopped and prepared ingredients together including the cilantro, lime zest, juice, minced garlic scapes or green onions, grated ginger, olive oil, and salt. Adjust any of these additional flavors to taste.
Serve on a bed of freshly washed greens with tortilla chips.