Cut them up, laminate them and away you go!
When I teach this lesson I have a role play phone and make my fraction pizza order... I ask the children, "Can I have 1 quarter of my pizza with cheese please?" etc.
Tried and tested with Reception children right through to year 2.
I have used high quality photos of the real toppings to make the pizzas more life like and have published the document in the best quality too so that it can be blown up to A3 size if you wish.
Download includes toppings:
1 spare pizza base