Ingredients
4 tablespoons unsalted butter
1 medium sweet onion, such as Vidalia, halved and sliced (1 1/2 cups)
Kosher salt
2 tablespoons unbleached all-purpose flour
1/4 teaspoon cayenne pepper
1/2 teaspoon ground turmeric
3 cups fresh corn kernels, plus milk scraped from cobs (from 3 to 4 ears)
2 cups low-sodium chicken or vegetable broth
Preparation
In a large saucepan, melt butter over medium heat. Add onion and 1 teaspoon salt; cook, stirring occasionally, until softened, 5 to 7 minutes. Add flour, cayenne, and turmeric; cook 1 minute more. Add corn kernels and milk, broth, and 2 cups water. Bring to a boil, then reduce heat to medium-low and simmer until corn is tender, 8 to 10 minutes. Remove from heat; let cool slightly. Transfer mixture to a blender, working in batches if necessary, and purée until very smooth, 2 to 3 minutes. (Strain through a fine-mesh sieve, if desired, for the silkiest texture.) Refrigerate until cold, at least 4 hours or, in an airtight container, up to 3 days. Season with salt; serve.
