Lists need to be instantiated before doing anything to them or using them. To do this, assign the field at its definition to a new instance of the List class with the type inside the < >.
If you try to instantiate the list oustide of the field definition, we can see that it gives us this error...
...which is telling us that because of the readonly modifier, we must instantiate it at the same time we define it or in the constructor, which we will learn more about in 2.4 and 2.5.
If we run the program and stop before the List instantiates we can see that its default is null.
Once we step over the instantiation, it brings us back to the instantiation of the Employee.
If we step over that...
...we can see that that Foods field is now an instance of a List with a default Count of 0.