Heat olive oil in a skillet over medium-low heat, and saute garlic and onions until the garlic begins to brown.
While the garlic and onions cook, beat the eggs, and mix in all the spices. Blend thoroughly. Pour the eggs into the skillet with the garlic and onions and stir constantly in a quick circular motion with a wooden spoon.
When the eggs have lost most of their moisture, add the mango, kidney beans, and tomatoes. Continue to cook and stir occasionally for several more minutes until the mixture has the desired level of moisture.
Transfer the mixture into a serving dish and toss with 1/2 of the fresh cilantro. Serve the remaining cilantro and cheese on the side.
To serve, layer fresh cilantro, egg mixture, cheese, and sliced avacado onto a fajita tortilla.