To boil frozen food with chicken without microwave Assume you have microwave food dishes with chicken and you have no microwave.

What is the recommended time to boil the food?
The temperature is less than microwave can reach.
I think the time should be longer, but how much?
There is no recommended time. You just cook it until it is done. 

If the food is pre-cooked (which is common with microwave-ready food), you only have to bring it to the temperature you like to eat it at. Else, you cook it until whatever is inside is cooked through. You can use a thermometer to determine the exact moment, but I wouldn't bother for a microwave-ready dish, as it is unlikely to be sensitive to overcooking.