Rinse beans. Soak in chicken stock in large pot 8 hours.
* Bring beans and stock to boil, reduce heat and simmer until beans are tender, 1 to 1 1/2 hours. Remove from heat and let cool.
* Melt butter in saucepan. Add chicken and saute over medium-high heat until browned, about 5 minutes. Add onion, chile and garlic and saute until onion is translucent, about 10 minutes.
* Puree half of cooked beans and cayenne in blender until smooth. Add cooked beans with cooking stock, bean puree and whipping cream to chicken and vegetables in saucepan. Bring to boil and season with salt and pepper to taste. Reduce heat and simmer 10 minutes.
* Ladle chowder into bowls. Top with tortilla chips and cheese if desired.