Preheat the oven to 375F (C). In a large bowl, toss potatoes, onions, olive oil, salt, and pepper together. Place the mixture on a baking sheet and roast until the skewer goes in side smoothly and the potato skin is crispy, about 30-45 minutes. Remove from the oven and set aside.While the potatoes are roasting, fry the bacon until crisp. Drain the extra oil on paper towels. After the bacon has cooled, chop into small pieces.In a large pot, bring chicken stock to a boil. Add the potatoes, chicken, both cans of corn, and thyme to the broth. Bring it to a boil again and once boiling, skim the scrum and fat from the soup. This is the important key to have nice refined soup, so don’t skip this process. Lower the heat to medium low and simmer for 5 minutes. Keep skimming during this time.Add heavy cream, salt, and pepper to taste, and cook until heated through, about 3 minutes. Serve into bowls and top with bacon and fresh thyme as garnish.