Over a medium heat, add the onions; sauté until tender for about 10 minutes. Add the oregano and cumin; stir for 1 minute, increase the heat to medium high, add the ground turkey; stir to break up until no longer pink.
Keeping the beans aside, add the rest of the ingredients, breaking up the tomatoes with the back of a spoon as you stir. Bring to a boil. Reduce heat, simmer 45 minutes, stirring occasionally.
Add the beans and cook for a further 10 minutes.
Discard the bay leaves. Ladle chili into warm bowls and top with chopped red onion, cilantro and sour cream. Serve immediately.