Think of this as a chowder for eating with your fingers. Finished with a small measure of crème fraîche (or whole-milk yogurt), the briny-sweet liquid released by the clams becomes a subtly creamy broth that’s as delicious as the clams themselves. If you can, use corn kernels cut from freshly shucked ears (you’ll need two good-sized ears to get the 2 cups kernels called for in the recipe), but frozen corn works in the off-season. Serve with oyster crackers, or with crusty bread for mopping up the broth.