In a heavy 8 quart pan, heat the olive oil over high heat. Add the chorizo and render the sausage for 3 to 4 minutes. Add the onions, celery, and carrots, saute for 2 minutes or until the vegetables start to wilt. Season the vegetables with salt and pepper. Add the kale, garlic, bouquet, chicken stock and red pepper flakes. Bring the liquid up to a boil and reduce the heat to medium. Simmer the soup for 30 minutes. Add the clams and continue to simmer for 8 to 10 minutes. Discard any shells that do not open. Stir in the cilantro. Reseason the soup with salt and pepper. The soup can either be served with clams in the shells or the clams can be removed from the soup, shells removed and added back to the soup. Serve the soup with crusty bread.