At its simplest, baked potato soup is just chopped baked potatoes in chicken broth and milk with some cooked onions as well. Cooking some bacon and then cooking the chopped onions in the bacon grease adds lots of flavor. Add some herbs, maybe some cheese and hot sauce. Put small bowls of toppings out for everyone to choose how to finish their soup. You can bake the potatoes the night before to get a head start. I’ve also used leftover (frozen) twice baked potatoes to make this.