Rub a pork butt all over with a mixture of 2 parts kosher salt, 2 parts oregano, 4 parts ground cumin and 1 part black pepper.
In the bottom of the pan (or slow cooker) place on large yellow onion chopped, 2 bay leaves, the zest and juice of one orange and 2 limes, and 1 tsp red chili flakes. Put the meat on top. Add 3/4 cup of chicken stock, water or beer. Cover it tightly and roast in a 275 degree oven for at least 7 hours or put in the slow cooker on high for 2 hrs and then on low for 6 hrs.
Use this meat to make cuban-type sandwiches, to make tacos or nachos or enchiladas, as a base for a pork chili, etc.