In a large pot, place beans and cover with 2 to 3 quarts of water. Soak overnight. Drain, or bring water and beans to a boil, reduce heat and simmer for 2 minutes. Allow to soak 1 hour. Drain.

In a large pot over high heat, place the 1/4 cup olive oil and the onions, and saute until tender, about 3 minutes. Add the chili powder and cook for 1 minute. Add the beans and the pasillas or hot peppers. Fill the pot with cold water until the beans are covered by 1" of water. Add 1 tb salt and black pepper to taste. Bring to a simmer, reduce heat to medium and cook until the beans are tender, about 1 1/2 to 2 hours. Remove the pasillas.

Stir in the roasted garlic and lime juice. Adjust the salt and pepper to taste if necessary. Add the corn and cook until hot, about 3 minutes. Ladle into warm bowl. Top with sour cream, Cheddar and scallion greens. Serve immediately.

To Roast The Garlic:

Preheat oven to 400 degrees. Coat the outside of a whole or partial head of garlic with olive oil or corn oil and place it in an ovenproof skillet. Roast on the lower rack of the oven until the skin is brown and the garlic is tender, about 30 to 60 minutes.