Curried Coconut Corn Soup

• 4 ears corn, yellow or white varieties, shucked
• 8 cilantro sprigs plus 2 to 4 tablespoons finely chopped cilantro leaves
• 1/2 cup finely diced red or white onion, trimmings reserved
• 1 tablespoon butter or olive oil
• 1 teaspoon coriander seeds or ground coriander
• 1/2 teaspoon cumin seeds or ground cumin
• 1/2 teaspoon ground turmeric
• 1/2 teaspoon hot or mild paprika
• 1/2 tsp. garam masala (optional)
  
• Sea salt or kosher salt and freshly ground pepper
• 1 can unsweetened coconut milk (1 and 1/2 to 2 cups)
• Juice of 1 lime, or more to taste

1. Bring 6 cups of water to a boil in a saucepan. Meanwhile, slice the corn off the cobs. I’ve been doing this in a shallow bowl/plate lined with a tea towel — a tip from Samin Nosrat’s Salt Fat Acid Heat.
   
2. Break the cobs and put them in the heating water with the cilantro branches and any onion trimmings (Note: red onion trimmings turn the stock very dark/murky—I leave them out). Simmer for at least 15 minutes--longer if you can--then strain.
3. Melt the butter in a soup pot over medium heat. Add the onion, cook for 3 to 4 minutes. If you’re using whole cumin and coriander seeds, toast them in a dry skillet over medium heat till they darken and become fragrant, then grind in a mortar and pestle. Add them to the onions along with the paprika and turmeric, and cook a few minutes more. Add in the coconut milk, the corn, the chopped cilantro, 1 and 1/2 cups stock, and 1 teaspoon salt. If the soup is too thick, thin it with more stock. Simmer over medium heat for 10 minutes. Squeeze in the juice of half of the lime. Taste, and add the juice of the other half if desired. Taste, adjusting the salt if needed. I add about another teaspoon of kosher salt (so 2 teaspoons total) but I like salt, so adjust to taste.