פירוש על עבודה זרה 75:2

If the food can be eaten while it is raw, then cooking does not make it edible for it was edible before. Thus even if it is cooked by a non-Jew, a Jew can still eat it. An example would be, for instance, a tomato.

This is the second version of the above statement. If the food is not “fancy” enough to be put on the table of a king to be eaten with bread then the prohibition does not apply.