How would I count this?

I am a preschool teacher and today was meet the teacher so our preschool ordered pizza for all the teachers to have lunch before the kiddos came to meet us.  I had the cheese topping off 1 slice of a large pizza and the cheese and pepperoni topping off 1 slice of a large pizza.  I did not have a way to measure it and want to log it on MFP but have no idea how to do it.  I did not touch the crust at all!!  Just cheese and pepperoni!