Cold Avocado Corn Soup with Cilantro Oil

Ingredients

• 2  avocado ()
• 0.3 cup cream sour
• 1  ears corn fresh
• 1 cup cilantro leaves fresh coarsely chopped
• 1  garlic clove smashed
• 3 tablespoons juice of lime fresh
• 0.3 cup olive oil 
• 0.5 teaspoon salt 
• 1  serrano chiles fresh stemmed coarsely chopped (including seeds)
• 4 cups water 
• 1.3 cups onion white chopped

Equipment

• bowl
• frying pan
• sauce pan
• ladle
• knife
• whisk
• sieve
• blender
• plastic wrap
• tongs
• cutting board

Directions

1. Roast corn on rack of gas burner over high heat, turning occasionally with tongs, until kernels are charred in spots, 4 to 5 minutes. (Alternatively, heat a dry well-seasoned cast-iron skillet and roast corn over moderately high heat, turning occasionally, about 10 minutes.)
2. Transfer corn to a cutting board and, when cool enough to handle, cut kernels from cob with a sharp knife, then cut cob into thirds.
3. Bring kernels, cob pieces, 4 cups water, garlic, salt, and 1/2 cup onion to a boil in a 3-quart saucepan and boil until liquid is reduced to about 3 cups, about 20 minutes.
4. Remove from heat and cool, uncovered. Discard cob pieces.
5. Purée corn mixture along with chile and remaining 3/4 cup onion in a blender, then pour through a fine-mesh sieve into a bowl, pressing hard on and then discarding solids. Return broth to cleaned blender.
6. Quarter, pit, and peel 1 avocado, then add to blender with 2 tablespoons lime juice and purée until smooth.
7. Transfer soup to a bowl and cover surface with plastic wrap. Cover bowl with plastic wrap and chill soup at least 1 hour.
8. Purée cilantro, oil, and salt in cleaned blender, scraping down sides of blender several times.
9. Pour oil into cleaned fine-mesh sieve set over a bowl and let drain 15 minutes (do not press on solids). Discard solids.
10. Halve and pit remaining avocado and scoop small balls from flesh with melon-ball cutter, then toss gently with remaining tablespoon lime juice in a bowl.
11. Whisk together crema and remaining 2 tablespoons water in a small bowl until smooth.
12. Season soup with salt and ladle into 6 shallow soup bowls. Divide avocado balls among bowls, then drizzle with crema and cilantro oil.
13. •Soup can be chilled up to 1 day.•Cilantro oil can be made 3 hours ahead and chilled, covered.