Preheat the oven to 200 degrees F (95 degrees C).

Season pork belly all over with smoked paprika, salt and black pepper.

Wrap pork in parchment paper; wrap a second time in aluminum foil; wrap a third time in another sheet of aluminum foil.

Place pork packet in a baking dish.

Bake in the preheated oven until tender, about 6 hours. Let cool in wrappings to room temperature; place cooled packet in the refrigerator and chill for 8 hours to overnight.

Unwrap chilled pork; reserve any rendered fat that falls away when unwrapping pork.

Cut pork into 6 equal portions. Cut 1/8x1/8-inch slashes in the fat-side of pork. Season with salt.

Heat 2 tablespoons reserved pork fat in a skillet over medium heat. Place pork belly, fat-side down, in hot fat; cook until browned on all sides and heated through, 5 to 10 minutes.

Transfer pork belly to a plate, drizzle with olive oil, and season with pepper.