Four eggs beaten with salt and pepper and stirred in butter until they just set. Ten minutes, three ingredients, and the difference between creamy and rubbery is the heat.
Low heat and patience. Eggs set at around 70°C, and a hot pan takes them past that in seconds, which is where rubbery scrambled eggs come from. Take them off while they still look slightly underdone: the residual heat in the pan finishes them on the way to the plate. More butter than the two teaspoons here gives a creamier result, because the fat coats the proteins and keeps them from binding too tightly. Note that these are plain scrambled eggs, not huevos pericos, which are the Colombian version with tomato and scallion cooked in.