SQLみたいにjoinしたテーブルのColumnを使うようにlinqのSelectManyでも同じようにしたい

SelectMany parent class add coulmun list.
なんやかんやでこうしたいことあるじゃないですか。

select 
    s.LastName,
    e.CourseID 
from Student s
left outer join Enrollment e on
s.ID = e.StudentID

using System;
using System.Collections.Generic;

namespace ContosoUniversity.Models
{
    public class Student
    {
        public int ID { get; set; }
        public string LastName { get; set; }
        public string FirstMidName { get; set; }
        public DateTime EnrollmentDate { get; set; }

        public ICollection<Enrollment> Enrollments { get; set; }
    }
}

namespace ContosoUniversity.Models
{
    public enum Grade
    {
        A, B, C, D, F
    }

    public class Enrollment
    {
        public int EnrollmentID { get; set; }
        public int CourseID { get; set; }
        public int StudentID { get; set; }
        public Grade? Grade { get; set; }

        public Course Course { get; set; }
        public Student Student { get; set; }
    }
}

こうできる

Student.SelectMany(s => 
    s.Enrollment.Select(e => 
        new {s.LastName, e.CourseID }));