The Mexicans have a similar dish it’s made with a porks stomach stuffed with all the naughty bits seasoned up with massive amounts of chili’s and slow cooked until mostly set. It’s cut up like blood sausage then put to the plancha the flat metal griddle screaming hot and crisped up then on corn tortillas with a verde salsa I have had it in Mexico City.
Oh, my.
(I got all excited when you mentioned salivary glands and ‘lengue’ - and now I’m a REAL mess :-)