Tried grass-fed Kobe beef for these meatballs the other day. Egg, basil, onion (fried), breadcrumbs, and the aforementioned Kobe.
Made a nice brown sauce with tomato paste, cumin, red wine, red miso, basil, and more.
And I must say, despite my skepticism, they were some of the best if not the best meatballs I've ever had. Absolutely delicious. My wife says that is due to my superior technique, but I am not going to take credit for this one. Hats off to the Kobe beef...it lived up to its reputation, even in ground up form.