I've only ever done this with duck and goose tongues, but I suppose some other sort of bird tongue would work. Who knows? Sauce these however you like. I have a collection of wild game sauces here.
Put the tongues, glace, salt, and duck fat in a vacuum bag and seal. If you don't have a vacuum sealer, just put everything in a small pot, and cover with water or stock.
Get a large pot of water steaming hot, but not simmering. If you have a sous vide water oven, set the temperature for between 175F and 190F. Put the vac bag with the tongues in it and cook gently below a simmer for at least 4 hours, and up to 10 hours. The longer you go, the more tender the tongues will be and the easier it will be to remove the bones.
When the tongues are ready, remove the bones by grabbing the root end of the tongue, feeling for the bone; it will bend down slightly. Holding the tongue with one hand, use the other to slide out the bone. Discard the bones... or use as earrings.
Arrange all the deboned tongues in one layer on a dehydrator tray and dehydrate on low hear for 2 to 4 hours. Or put them on a rack in an oven set on warm. If you have a convection oven, turn it on for air flow. You can to all this up to 2 days before you want to serve them.
To fry, dust the tongues in the starch and fry in 350F oil for 2 to 3 minutes, turning so they're golden brown all over. They should puff up a bit. Fry in batches so you don't crowd the pot.
Serve piping hot with the sauce of your choice.
Notes
Note: Cook time is only fry time, not braising time.