Step 1

Heat oil in a large, nonstick pot or cast iron Dutch oven until shimmering. Add corn kernels, chopped onion, chili powder, 1/2 teaspoon kosher salt, and 1/2 teaspoon black pepper. Cook over medium-high heat, stirring frequently, until onions are soft and corn is lightly charred in spots, about 8-10 minutes.

Step 2

Add garlic and cook until fragrant, 1 minute. Remove 1-1/2 cups of corn mixture from the pot and set aside. Stir broth and 6 stripped corn cobs into the pot, scraping up the brown bits on the bottom. Bring to a boil, reduce heat, and simmer for 20 minutes.

Step 3

Use tongs to remove corn cobs from pot and discard.

Step 4

Stir sour cream and Cotija into the soup. Transfer soup to a blender or food processor (in batches, depending on the size of your unit for safety) to puree until smooth.

Step 5

Return soup to pot and if needed, gently reheat to desired serving temperature. Stir in half (3/4 cup) of the reserved corn mixture, lime juice, and 2 tablespoons chopped cilantro. Season to taste with salt, pepper, and chili powder.

Step 6

Toss remaining 3/4 cup corn with lime zest and 2 teaspoons chopped cilantro. Serve soup, topped with a few spoonfuls of the corn mixture, and an extra sprinkling of Cotija.