Entity Framework - Inverse Property Relationships?

I'm having trouble understanding how I can accomplish the following relationships:

public class Organisation {

    public Guid Id { get; set; }

    // Have a single user as an administrator of a company
    public User AdminUser { get; set; }

    // All users associated with the company (including the admin)
    public ICollection<User> Users { get; set;}
}

public class User {

    public Guid Id { get; set; }

    // Each User must be associated with an Organisation.
    [ForeignKey("Organisation")]
    public Guid OrganisationId { get; set; }
    public Organisation Organisation { get; set; }
}

Is that something that can be done via Inverse Properties? I understand that they are a solution to define multiple relationships between the same entities, but I'm struggling to see how I can set this up for my situation. Could someone help out with example code?

Thanks in advance.