make the rub by roasting the corriander in a hot skillet for about 3 minutes or until you can smell the corriander. Grind this and the oregano with a mortar and pestle or spice grinder. Add all other rub ingredients and mix well.
Rinse and dry the pork loin.
Using a sharp, long knife cut 1/2 inch above the cutting surface as you roll the loin out. You should have a continuous slab of meat once complete.
Apply a little rub to the surface.
layer the spinach over the surface.
add the cheese.
roll the pork loin and tie with butcher twine.
Sprinkle the rub over the outside surface and rub it inches.
Place it on a grill so that it cooks indirectly and is not directly over the coals. If using propane, cook over the burners not lighted.
If desired, add smoke wood, chips or a foil packet with wood chips.
Cook until internal temperature of the meat is 160°F.
Let the roast rest 15 minutes or so before slicing.