Why green? Fire roasted chilis, tomatillos and jalpeños, my friend. They combine for a heat that wards off any winter chill, and pork butt AND Italian sausage make this one heck of a hearty meaty chili. It's really important you take the time to brown the meat (and the bone) to get maximum flavor. To save time, ask your butcher to cut the pork off the bone into 1 inch cubes -- but be sure to ask for the bone, too!
A larger pork butt by a couple pounds will work fine with this recipe...you'll just end up having more portions or leftovers!