makes 8 servings
6 ears of corn
4 cups low-sodium vegetable broth
2 cups water
1 tablespoon unsalted butter
1 medium onion, chopped (about 2 cups)
2 medium potatoes, peeled and diced (about 2 cups)
fine sea salt and freshly ground black pepper
1. Shuck the corn, then use a serrated knife to strip the kernels from each corn cob into a bowl. Place the cobs in a large stockpot with the vegetable broth and water. Bring to a boil, then cover, reduce the heat to medium low, and simmer for at least 10 minutes.
2. While the cobs are simmering, melt the butter in a medium stockpot over medium-high heat. Add the onion, potato, and salt and pepper, and sauté until the onion is softened, 5-8 minutes.
3. Carefully remove the corn cobs from their cooking liquid and pour the stock into the pot with the onions and potatoes. Bring to a boil, then reduce the heat and simmer until the potatoes are tender, 15-20 minutes.
4. Use an immersion blender to blend the soup until smooth and velvety. Alternately, carefully puree the soup in a blender in several batches, then return to the stock pot.
5. Stir the corn into the soup and simmer until tender, about 5 minutes. Season with additional salt and pepper to taste. Serve immediately.