Sauté onions in olive oil until translucent. Add red pepper and cook until crisp tender. Add garbanzo beans and BBQ Sauce. Cook until sauce cooks down, which will take a few minutes. Add salt and pepper, to taste.
Heat corn tortillas on stove, by charring them directly over gas flames, being careful not to burn them. You could also heat them on a skillet over medium heat (without oil) for about 30 seconds on each side.
Pile BBQ chickpea mixture into each one and top with chopped mango and pickled peppers and onions.