OK as we move along now we have two containers. I gave you a suggestion as to finding heating elements.
How you go about this is up to you. Nobody here will do an assignment for you. What is expected is you read the forum sections about how to get good help and you posting your code and proposed schematic or drawing of your project. A hand scribed drawing is fine.
Using an Arduino UNO for example you have DIO (Digital In / Out) pins which can easily drive a SSR (Solid State Relay). That powers your heating element(s).
There are several ways to get to where you want to be, your project and your choice.
I will add that you want to be concerned and control temperature from the container with the food in it so your temperature sensor goes there.
Ron