Season the pork with salt and pepper. Heat a large cast-iron casserole. Add the pork, fat side down, and cook over moderately high heat until browned all over, about 12 minutes total. Transfer to a plate. Add the tomato paste to the casserole and cook over moderately low heat, stirring, until deep red, 2 minutes. Add the paprika, cloves, allspice and brown sugar and cook until the sugar dissolves, about 30 seconds. Add the vinegar and bring to a boil, scraping up any browned bits. Add the molasses, ketchup, ground coffee and water and bring to a simmer.