In her presence, place one piece of the food in her empty dish and say the special word. Say the word again after she eats the first piece. Place another piece of the food in her dish and say the special word again. Then walk out of the room. Repeat the procedure in 5 minutes.
Cats learn very quickly when they are motivated.
Follow this procedure for the next several days. Make certain it is nutritious. Choose a dry, crunchy snack that is also good for the teeth. Don't forget, this is to be a small snack, not a small bowl of dry food. Otherwise, your kitty might gain unwanted weight.