pan fry bacon and chopped onion until very crisp (so it can be crumbled), while cooking bacon boil the 5 lb bag of red potatoes with the skin on (clean first). Drain the cooked bason/onion on a paper towel and set aside. When potatoes are tender, drain. Let it cool slightly. Cut-up in 1 1/2 inch chunks and place in a large bowl. Drizzle red wine vinegar sparingly to potatoes. Add bacon/onion mix, salt, pepper, mayonaise (a little at a time) depending on your taste for mayonaise. I don't make it soupy with mayo. Mix well, sprinkle with parsley and serve. Best when served still warm, but great cold too. Leftovers can also be reheated.