As a kid, I dreaded BBQ nights. It was always a meal of well done (charcoal) meats and foil wrapped potatoes drier than Death valley soil. It wasn’t until I was well into my adulthood that I even started to swerve towards thinking of the BBQ as anything but blackened charred food. It’s also probably the reason I like my steaks blue.
I started adding the onions on the bottom of the foil to prevent the potatoes from burning on the bottom. It resulted in a sweet caramelizing effect, and added not only flavor to the side, but also keep things from drying out and some nice color on the otherwise bland potato. You can add a pat of butter to the top before you wrap the spud to create a bit more moisture and give some added taste.