I just did the beef heart thing. Cut up a kilo of beef heart into five chunks. Vacuum sealed them with some rosemary, thyme, garlic powder, and a tablespoon of beef drippings. Into the sous vide at 70 ºC for 24 hours.
Then diced up the cooked heart and prepared it as I normally would in a Römertopf, using onion, tomato, mushrooms, smoked speck, salt and pepper, sour cream, and a dash of red wine, plus the juices from the sous vide bag. Into the oven at 220 ºC for about 100 minutes.
Upshot was that the dish came out tasting very much like it always does, but the heart had melt-in-the-mouth texture. It’s a big improvement over just cooking heart in a Römertopf for two hours. I’ll definitely continue with that method. In effect, sous vide is just a pre-cooking step, and all the other things are exactly the same. And the meat is oh so very much more tender…