Heat the canola oil in a large pot over medium-low heat. Add the garlic, onions and poblanos and cook for about 10 minutes or until soft. Add the chili powder and continue to cook for approximately 3 minutes, stirring frequently. Add the heavy cream, chicken stock, hominy and shredded chicken thighs. Bring to a simmer, then reduce the heat to the lowest possible setting and cook for 45 minutes.
To finish, add the white beans and masa harina. Bring back to a simmer to thicken, stirring frequently. Season with kosher salt. If desired, adjust the consistency with either more chicken stock or masa harina.
Serve with fontina cheese, tortilla chips, sour cream and lime wedges.