Symbolism, Imagery, Allegory
It's a cauldron, really. The kind of thing you'd expect the Weird Sisters in Macbeth to be dancing around in the middle of their clearing. And yet…this pot, though magic, doesn't appear to have any evil in it. Or on it. Or around it. Not one drop, dot, or iota.
We first see the pot on the cover of the book, held lovingly by the title character. It appears, as any cauldron held by a woman in an apron and headscarf would, to be a harmless domestic prop. And in many ways, it is. Under Strega Nona's command, the pasta pot produces what is necessary—nothing more, nothing less. It's only when the pot falls into the wrong hands, Big Anthony's big mitts, that it becomes a problem. So what does that mean?
Well, the pot itself is magic, and since its particular brand of magic involves producing food, we can see it symbolizing not just Strega Nona's magical abilities, but also the very Italian tradition of feeding people. Lots of people. As in, everyone who walks through your front door. In this way, the magic pasta pot, as a central item in the story, brings Italian culture front and center as well.
And when Big Anthony, who doesn't pay attention, creates havoc by using the pot improperly, we further see the importance of understanding one's heritage and treating it with the respect it is due. By disregarding Strega Nona's warnings and using the magic pasta pot without proper training and permission, Big Anthony nearly wipes out his entire village. Not cool, Big Anthony. Not cool at all.