In a large pot, heat butter and olive oil over medium-high heat. Add onion and garlic and cook, stirring occasionally, until tender, about 5 minutes.
Add next six ingredients (salt through pepper) and cook until fragrant, about 30 seconds.
Add ground chicken. Cook, stirring and breaking up meat with a spoon, until no longer pink, about 5 minutes.
Add green chiles and cook, stirring occasionally, for 2 minutes.
Add beans and chicken broth. Bring to a boil and then reduce heat to a simmer. Lightly smash some of the beans with the back of a spoon to release their starch. Simmer, stirring occasionally, until the liquid has thickened, 10-15 minutes. Season with additional salt and pepper to taste.
Divide chili among four bowls and top with corn chips, avocado, cilantro, Colby-Jack cheese and jalapeño, if using.
Recipe by Two of a Kind at http://www.twoofakindcooks.com/white-chicken-chili/