For the overnight flight, CX 843/143, they serve supper after takeoff and breakfast prior to landing.
On CX 843, instant noodles are available on request in PE and Y (and more substantial snack selections in J) and there are packaged snacks in the galley for PE and Y, and for J cabin, you have to ask crews for them. CX 143 was medium haul (along with all Australian and Middle East flights) so they only serve two meals in all cabin classes. Perth is always two hot meals. Dubai/Riyadh have one hot meal and one hot snack.

CX 831 and 841 are main meal (lunch) after takeoff and light dinner mid-flight with snacks on request.

Carfield