Preheat the oven (with a cookie sheet in it) to 425 degrees.
While it's heating, cut potatoes into chunks and toss them with enough olive oil to coat and season with salt and pepper. Lay out a single layer of potato chunks on aluminum foil and double over to form a packet (still single layer). Make several small packets (I had 3 square and one long one to fit down the side of the pan).
Pull the hot pan out of the oven, place the packets on it, and roast the potatoes for about 20 to 25 minutes. Stick a knife through the foil into a big chunk to test for doneness.
While the potatoes are roasting, cook up the "bacon" in your preferred method. The only word of advice: make sure it's crispy! You'll be crumbling it once it's cool to mix into the salad. If you have vegan bacon bits intended for salad topping these would probably work as well.
When the potatoes are done cooking, let them rest in the packets for 5 minutes while you put the Nayonaise, onions, and bacon in a bowl. Dump in the potatoes and mix it all up.
I personally think this salad is better warm, but still QUITE delicious when it's cold--I just had some!