Fresh summer corn is best served in the simplest ways. Too many other ingredients and you'll miss the delicate caramel and grain flavors that underlie the initial burst of sweetness. This recipe uses both the corn kernels and the milk scraped from the cob using the dull side of a knife.
Shuck the corn and score each row of kernels with a sharp knife. Use the dull side of the knife to scrape the pulp and corn milk from the cobs into a wide bowl. Pour the whole milk into a small saucepan over medium heat and bring to a low simmer.
Melt the butter in a 4- to 5-quart heavy-bottomed pot over medium heat. Add the onion, salt, and pepper, and cook, stirring often, until translucent, about 6 minutes. Stir in flour and corn and cook for 2 minutes. Add whole milk and bring to a simmer; the mixture will thicken. Serve hot, garnished with parsley.