Colombian Chicken, Corn, and Potato Stew

INGREDIENTS

• 3 ears corn, cut into 1-inch rounds, or 2 cups kernels (10 ounces)
• 1 pound (thawed if frozen), quartered, or russet (baking) potatoes
• 1 large white onion, chopped
• 1/4 cup drained capers
• 1 tablespoon dried guascas or oregano
• 1 pound Yukon Gold potatoes
• 2 quarts water
• 1 cup crema, or 1/2 cup heavy cream mixed with 1/2 cup sour cream
• 2 cups reduced-sodium chicken broth
• 3/4 cup chopped cilantro, divided
• 1 pound boiling potatoes
• 1 whole chicken (about 3 1/2 pounds)
• 3 (6- to 8-ounces) firm-ripe avocados, cut into cubes