- 5 ears sweet corn
- 2 medium onions
- 1 tablespoon vegetable oil (or olive oil or butter)
- 1 teaspoon fine sea salt (plus more to taste)
- 4 cups water or vegetable stock
- Optional garnishes:
- diced roasted green chile
- chopped cilantro
- diced avocado
- diced tomato
- crumbled goat cheese
Shuck the corn removing the tough husks as well as the silky threads. A moment to remove as much of the corn silk as possible will save you from picking it from your teeth later!
Using a sharp knife in a very large bowl, cut off the corn kernels from the cobs. Use the blunt side of your knife blade to scrape remaining liquid and corny bits into the bowl after you grate each cob. Set aside this luscious raw corn puree.
Peel and chop the onions. In a large pot, heat the oil or butter over medium heat. Add the chopped onions and 1/2 teaspoon of the salt. Cook, stirring occasionally, until the onions wilt, about 3 minutes.
Meanwhile, peel and chop the corn cobs into pieces to fit your pot. Add the cobs and water or broth to the pot. Bring to a boil. Cook until the onions are very soft, about 10 minutes.
Remove corn cobs and add the corn purée. Cook until everything is heated through, about 2 minutes.
Puree with an immersion or in batches in a blender or food processor (do this in small batches to avoid splashes and burns and cover the top with a clean kitchen towel to catch any hot splatters). For a smoother finish strain through metal mesh strainer.
Add salt to taste. (Do this at the temperature at which you plan to serve the soup; chilled soup will need more salt than hot soup because cold dulls the flavor.) Note that you will need to add a fair amount of salt if you used water as your base liquid. Keep adding salt, about 1/4 teaspoon at a time, and tasting until you notice a jump in the corn flavor.
Garnish with roasted chile, avocado, tomato, cilantro, or cheese, if you like.