You can have takeaways as long as you syn them. If you want one on a Saturday night, you could always save some syns from earlier in the week to accommodate the takeaway.
eg, Beef in black bean sauce for a 360g serving is 5 syns on a red day or 16.5 on a green day. If you were doing red you'd have to count any rice as syns, or a green count the beef as syns with rice which would be free.
If you had a beef chow mein (which has noodles in it) a 450g serving is 13.5 on a red day and 8.5 on a green day. Considering you can have 10-15 syns per day, a beef chow mein is still within your syns allowance for that day anyway.