Cut kernels off corn cobs using a sharp knife. Toss kernels with oil, spread on a baking sheet and roast for 25 minutes, or until softened and lightly caramelized. In large saucepan over medium heat, cook bacon until brown. Add celery, carrots, and onion to bacon and sweat for 10 minutes. Add flour to the vegetables and cook for 3 minutes. Add corn, potatoes, and heavy cream and gently simmer for 45 minutes or until reduced and thickened. Season with thyme, sea salt, and freshly ground black pepper, to taste. Whisk in truffle butter and serve.