My girlfriend is a terrible cook. I'm gonna start making snide little remarks so she can get a clue.
You really think that'll help the situation?
I'm hoping that she'll realize that her cooking isn't very good and it needs to improve.
Or you could just let her know in a polite way. I don't see why you need to be passive aggressive. Why not cook for yourself?
I'm too tired to cook.
If you love your girlfriend and respect her, you'll let her know her cooking isn't top notch in a respectful way.