Sweetbreads are thymus glands, usually from calves. They have a flavor similar to lamb fries (lamb testicles), with a springy texture, says chazzerking. In French cooking, they’re traditionally parboiled, peeled, and braised with a demi-glacé sauce, and they can also be lightly floured and pan-fried. A more American preparation is to batter and deep-fry them, says fromagina—“about as far from Ris de Veau Financier as you can get! More like Ris de Veau Truckstop.”
If you’re going to cook sweetbreads at home, absolute freshness is key, says Harters, so get them from a source you trust—go to a butcher rather than the supermarket, if possible.
Board Link: What is a Sweetbread?