Heat oil in a large Dutch oven over medium-high. Add corn kernels, and cook, stirring occasionally, until lightly charred, about 10 minutes.
Add butter to Dutch oven, and stir until melted. Add onion and garlic; cook, stirring occasionally, until onion is translucent, about 3 minutes. Sprinkle in flour, salt, cumin, and 1/2 teaspoon of the chili powder; cook, stirring constantly, until fragrant and thickened, about 2 minutes. Stir in chicken stock and green chiles; bring to a boil, stirring occasionally. Reduce heat to medium, and simmer until flavors meld together about 5 minutes.
Stir in cream, and cook, stirring often for 3 minutes. Remove from heat. Sprinkle each serving with cheese, cilantro, and remaining 1/4 teaspoon chile powder. Garnish with jalapeƱo slices and lime wedges.