Preheat oven to 350 degrees.
In a small mixing bowl, combine all the above ingredients except for the pork, cornstarch, and ginger beer. Blend measured ingredients well, and then add several tablespoons of ginger beer to the spice mixture to help make a thin paste. Reserve the remaining ginger beer for basting and pan drippings.
Smear spice paste all over the pork. Place on a roasting pan and lay a sheet of aluminum foil loosely over top. Slow-cook at 350 degrees 45 minutes to 1 hour or until internal temperature reaches 155 degrees and outside is golden crusted. Baste several times and continue to lay foil back over top each time. Remove from oven and let roast rest 10 minutes before slicing. Pour pan drippings and spicy liquid into a small saucepot and thicken with cornstarch slurry. Strain and pour over the roast pork slices.