authentic mexicans from the straight Michoacan taught me how to make carnitas about 15 years ago. They braise in a big cauldron for 3-4 hours, then basically pull the meat, after which they throw the chunks into a very hot oven - which crisps the bits and then they chop it all up and serve. As Jose Juan explained it, back in Michoacan they would braise and add fatback to the braising pot in the latter stages of the cook so as to fry the meat. No matter the method, aggressively seasoned pork butt slow cooked and then fried (lard or oven) is ridiculously good.