Does the use of "על" in the above sentence mean you don't need "את" or is there another reason you don't need the direct object indicator?
I'm also a learner, but I tried to look this up. I think the reason is that "direct object" means "direct object of a verb" - you don't use את if you're referencing the object of a preposition.
I wrote "dish" instead of "plate" and got marked wrong. Puh-leeeez.