Mash anchovies, fresh rosemary, and fresh thyme in a small bowl. Set aside.
Place pork loin chops in a single layer on a baking tray. Sprinkle all over with salt, ground pepper, and garlic powder on both sides.
Brush rosemary anchovy marinade onto both sides of pork chops. Allow them to marinade in the refrigerator for one hour.
Preheat grill to high (about 400°F/200°C). Brush some oil on the grates.
Arrange pork chops on the grates and close the lid. Temperature will drop to 350°F/180°Grill pork chops for 5 minutes at 350°F/180°C.
Open the lid and flip pork chops and grill for another 5 minutes. Close the lid. Watch closely to avoid flare-ups by opening the lid occasionally. Move pork chops to a different part of the grill to avoid charring if flare-ups occur.
Open the lid and transfer pork chops to the top rack in the grill. Cover the lid and continue to cook for another 5 minutes. Temperature will rise to about 400°F/200° with the pork chops off the grating.
When cooked, pork chops should have an internal temperature of about 170°F/77°C. Remove pork chops from the grill onto a platter. Cover loosely with aluminum foil and allow them to rest for 5 minutes before serving.