Sweat the onions, bell peppers, and celery in the rendered bacon fat in a heavy soup pot over medium-high heat.
Once the onions become translucent, add the kidney beans, ham hocks, bay leaves, and cayenne, then add water to cover by 2 inches.
Increase the heat and bring the water to a boil. Cover the pot, reduce the heat to low, and allow the beans to slowly simmer for 2 hours. Periodically stir the beans to make sure that they don't scorch on the bottom of the pot, adding water if necessary, always keeping the beans covered by an inch or more of water.
Continue cooking the beans until they are creamy and beginning to fall apart when they're stirred.
Remove the ham hock meat from the bones, roughly chop it, and add it back to the pot of beans.
Stir in the green onions and season with salt, black pepper and Tabasco. Serve with the Basic White Rice.