Saute the sausage over medium-high heat for 5 minutes, stirring to prevent sticking and to break up the meat. Add the onions and continue to cook until the onion is soft. Reduce the heat to medium, add garlic, chilies and tomato sauce, cook for 5 minutes.
Add the beans, bananas and enough of the bean liquid or water to make a thick, dip consistency. Mash the beans slightly with a potato masher and mix well. Cook and cover on low heat for 5 minutes. Serve warm with tortilla chips.