If it is a boston butt that they have sliced..They would be called pork steaks here. Retailers do this at times...it is a form of cross-merchandising..They will advertise butts at 99 cents per lb. and display the steaks at 1.19 or higher per lb...this helps off set the lower price on the whole butt...They do the same thing with rib-eyes...whole rib-eye is on price point....small packages are a higher price point.
A couple of ideas as to cooking them: (1) braise them in a nice brown gravy with lots of garlic, onions, peppers, whatever..be patient they will get very tender..Serve over rice or biscuits..or both!!!
(2) you can cook them on your grill....used direct heat to brown/sear slightly...then go indirect until they are done...do not over cook...you miight want to foil them for a while towards the end....sauce...or not.
At one time retailers would slice the butt thick and then cut the slice down the middle.. presenting them as "Western style ribs" Obviously they are not true ribs....but rather an excellent marketing tool. So boston butt..sliced is pork steaks...slice again Western Style ribs...and probably a few other names out there.. Bottom line it's all part of the pork shoulder..the boston butt portion.
Hope this helps!