Preheat the oven to 450ºF (232ºC). For a convection oven, reduce cooking temperature by 25ºF (15ºC).
Cut baby red potatoes into halves, and cut the onion into wedges. Shred or cut the rotisserie chicken into small bite-size pieces and set aside. In a large bowl, toss potatoes, onions, olive oil, salt, and pepper together. Transfer them to a baking sheet.
Roast until the skewer goes inside smoothly and the potato skin is crispy, about 25-30 minutes. Remove from the oven and set aside. While the potatoes are roasting, cook the bacon in a frying pan until crisp. Transfer to a paper towel and drain the extra oil. After the bacon has cooled, chop into small pieces.
In a large pot, bring chicken broth to a boil. Add the roasted potatoes and onions, shredded chicken, both cans of corn, and a sprig of thyme to the broth. Bring it to a boil again and once boiling, skim the scrum and fat from the soup. This is the key to have nice refined soup, so don’t skip this process. Lower the heat to medium-low heat and simmer for 5 minutes. Keep skimming during this time.
Add heavy cream, kosher salt, and pepper to taste, and cook until heated through, about 3 minutes. Serve into bowls and top with bacon and a tiny sprig of thyme as garnish.
You can keep the leftovers in an airtight container and store in the refrigerator for up to 3-4 days or in the freezer for 2 weeks.