I saw this done in Brazil last year and, cheap as I am, only bought plantains on Fresh Direct the other day because they were on offer. Hey, we British maintain a wartime attitude at all times, even when there isn't a war on. I haven't reverted back to canned milk and powdered eggs. Yet.
These were really easy; I split them in two, scored them like mangoes and set them face down on a very hot skillet for about 3 minutes. They then went into the oven for another 10 minutes at 350°F and we ate them with Bhutanese red rice and a Khmer fish curry. I'll have to make the curry again and take pictures, as we ate it too quickly.