When you go to a restaurant and order sweetbreads, or go to a Simcha and are served sweetbreads you are getting the Thymus Gland.
Actually, you get whatever they decide to serve you. Since they know most people don’t know what it is anyway, they just take the mushy stuff from when you cook ground turkey, and add potato starch to make it a little more jellish, and some other junk, and roll it on out.