In a nonstick pan thoroughly cook ground bison on medium-high heat until no longer pink, breaking apart into crumbles. Remove bison from pan and set aside.
Return pan to the cooktop, add butter and melt over medium-low heat.
Add red onion, poblano, and garlic to the pan. Saute for 4 minutes, until onions are translucent.
Add cumin, chili powder, and salt. Stir to coat the vegetable mixture.
Add milk, American cheese, and cream cheese. Cook at low heat, stirring often,until cheese is melted and smooth.
Stir in green chilis, bison, cilantro, and more salt if needed.
Pour queso into a serving dish. Optional: top with pico de gallo.