Cut the corn: Remove the kernels from the 4 ears of corn by sliding a sharp knife down each cob. You should have about 3 cups corn kernels. Set the kernels aside and place the stripped cobs in a large pot.
Make the corn stock: Add the 8 cups water, reserved onion trimmings, garlic skins, jalapeño cores, and 1 teaspoon kosher salt to the pot with the corn cobs. Bring to a boil, then reduce to a simmer and cook for 1 hour. Add celery, bay leaf, black peppercorns, or fresh parsley if desired.
Sauté the vegetables: Heat the 3 tablespoons olive oil in a large stockpot over medium-high heat. Add the 2 chopped small red onions and season with salt and freshly ground black pepper to taste. Cook for a few minutes, then add the 3 chopped garlic cloves, 2 chopped jalapeños, and about 3 cups corn kernels. Cook for about 5 minutes, or until the vegetables are tender.
Toast the chile powder: Add the 1 teaspoon chile powder and cook for 1 to 2 minutes, stirring, until fragrant.
Add the stock: Place a fine-mesh strainer over the vegetables and carefully pour the corn stock through it. Discard the corn cobs and other solids.
Simmer the soup: Bring the mixture to a boil, then reduce to a simmer. Cover and cook for about 30 minutes, or until the vegetables are very soft.
Blend and add the cream: Carefully purée the soup in a blender, working in batches if necessary, until smooth. Return the soup to the pot and stir in the 1 cup heavy cream. Reheat gently and season with additional salt and freshly ground black pepper to taste.
Make the crumble: Combine the 1/3 cup crumbled blue cheese, 2 tablespoons chopped fresh cilantro, and 1 thinly sliced cayenne or Thai bird chile in a small bowl.
Serve: Ladle the soup into bowls, top each serving with the blue cheese-chile crumble, and serve immediately with lime wedges.
