To do this, first change Recommended by to not Used.

This is done by navigating to:
  1. onRecord > Settings > Course Request Setup
  2. Select the correct School Year
  3. Next to each Grade Level and change the Signup End Date to a Date beyond today

Then the Teacher Task for Course Recommendations needs to be disabled. This can be done by navigating to
  1. Core > Users/Access > Profile > Manage Roles
  2. Click on Teacher
  3. Click Tasks
  4. Click Edit
  5. Next to Course Recommendations, unmark the checkbox
  6. Click Save
This will enable Parents/Students access to Course Requests but no Teacher Access to Recommend.