Heat some oil in a large Dutch oven or heavy pot and brown the ground beef, adding the onions and jalapeno peppers while the beef is still a little pink. Cook until the onions are tender and transparent. Combine the chili seasoning mix and add it to the ground beef and onions. Stir to combine.Add the remaining ingredients (except for the sour cream and cheddar cheese), bring to a boil, reduce the heat to low and cook until the beans are tender, or about one hour, stirring occasionally to prevent bottom from burning. Add more chili powder and salt to taste.Serve with a dollop of sour cream and some shredded Cheddar cheese along with some cornbread muffins.