>>OP
Offal is the true test of a chef; any monkey can sear a steak and check doneness, or put together a braise. But to take something like a kidney, and turn it into something beautiful takes serious care and experience, and a fair bit of dedication. You have a far narrower margin of cooking and pairing but the rewards are seriously great to the guy who bothers. I am a massive fan of offal and some of the best dishes I've composed/cooked feature them. Try making a terrine of pig's liver with cornichon, shallots, capers, parsley, chervil, and lard. Or lamb's sweetbreads with marjoram, paprika, and garlic. Alternatively check out Fergus Henderson's 'Nose to Tail eating'
Aside from being delicious, they are often cheap, super nutritious, and fun to learn about.
Let me know if anyone wants some cool recipes