Did you know that starting next month we're promised pizza?
Do you mean that you're getting paid in pizza?
I was promised pizza as payment once I finish working with these tasks.
If they promised you pizza, then I would expect a pizza. You can expect a friend to keep their promise about things like this.
Pizza is a fucking currency
No it is not, and pretending that pizza is a currency will hurt you as you won't be able to use it for anything real outside of eating. You may end up out on the streets without any actual money to use for things.