Rub racks of lamb with 1 tablespoon of olive oil each and dust both sides with rosemary salt.
Place lamb on rotisserie spit in opposite directions and lock down the clamps.
Place spit on rotisserie with a drip pan beneath the racks to collect any drippings.
Close lid and allow lamb to cook at a high temperature for 20-25 minutes.
Remove from heat. Let rest for 5 minutes before slicing and serving.