Sprinkle the chicken cubes with salt and pepper while the oil is heating in a skillet over medium heat.

Add the chicken pieces and cook, stirring, until done. (The time will depend on how large your chicken pieces are.)

Add the green onions and cook another minute, stirring.

Add the vinegar, lime juice and oregano and stir well, then cook over medium low heat until most of the liquid has evaporated.

Heat a cast iron skillet over high heat and warm the tortillas one at a time, laying them down in the skillet for a minute, then turning over until warmed through.

Put some chicken in each tortilla and let everyone top their tacos the way they like at the table.