Score pork all over.
In a food processor, blend all the rest of the ingredients together, adding oil in last.
Rub paste all over pork. Cover with plastic wrap and refrigerate at least six hours, preferably overnight.
Bring pork out of refrigerator an hour or two before cooking. Preheat oven to 450.
Put pork in shallow, rimmed pan and cook for 35 minutes.
Reduce heat to 325 and cook another 3 to 4 hours. (Boneless roasts will cook faster.)