i don't mind if the food is nice and have variety.

What you could do is make it such that the box can be put into microwave oven for warming. This way, you don't need to deliver the food while it's hot. Can deliver early as customers just need to warm it up to eat. Those who are busy can keep it until 3pm or 4pm cause sometimes they might be too busy to eat.

You can look for disposable boxes. If can't find any that is suitable for microwave and keep food fresh, then get customized boxes. Take deposit from customers...for eg charge RM10 for the food + box. When customer return the box, refund back RM5. Assuming the box cost RM5.

Just my 2cents. Cause this thing have potential. It is successful in some parts of Asia. However, I have seen many people try this in Malaysia and failed.