It is definitely a very heavy cheddar cheese sauce.
If you are able to come up with the names of those places, let me know. And because both a Hot Brown and Turkey Devonshire can vary so much from place to place, the differences between them is practically negligible.
Have you had the Turkey Devonshire at Union Grill before?
I did see the show where Taste of America went to The Lamont and Union Grill for Turkey Devonshires. If I remember corrctly, The Lamont doesn’t even have them on their regular menu.