I am having a hard time finding good, reasonably low fat precooked chicken burgers currently, presumably due to COVID; I used to buy these for reference. As such, I figured I'd prepare my own.
I'm shredding (in a Cuisinart) raw, boneless/skinless chicken thighs (with most of the fat removed that's external but leaving the intramuscular fat), and then adding caramelized onions, cooked garlic/bell peppers, and spices or BBQ sauce, then forming into patties, placing in a vacuum bag, sealing, and cooking in my sous vide at 150 for an hour or so. Then I let them cool for a bit, and put them in the freezer. I prepare them from frozen in a pan (directly, no oil or steam beyond what they produce themselves).
Batch one went well, except that they don't keep their shape well. Between sous-vide and freezer, they end up in really odd shapes or even bent (presumably because I don't have a perfect spot).
Are there things I can add to the recipe, or to my technique, to help them stay a bit more flat and less thin? The main thing I've seen that I'm not including is bread/breadcrumbs; I'd prefer to not include that (as it's empty calories), but if this is the specific reason it's in there I could reconsider. I'm also using thighs, not breasts, in part as they have the fat profile I think is best - but if breast meat would do better in this application, I could certainly switch.