2Combine corn kernels and 1 tablespoon olive oil in a baking dish; stir to coat corn kernels in oil.
3Roast corn in preheated oven for 20 minutes.
4Heat 1 tablespoon olive oil in a large pot over medium heat. Cook and stir onion, carrot, celery, and garlic in the olive oil until tender, 5 to 7 minutes. Stir chicken broth, roasted corn, potatoes, light cream, cream-style corn, parsley, salt, and pepper into the vegetable mixture; bring to a boil.
5Melt butter in a small skillet over medium-low heat; stir flour into melted butter and whisk until a paste forms and begins to thin, about 5 minutes.
6Stir roux into the chowder; continue cooking until chowder is thickened, about 30 minutes.