The Denver cut, or under blade steak (as opposed to the top blade or flatiron steak), is part of the chuck that is very tender and highly marbled.
While not as tender as the teres major in the shoulder, this cut offers something unique in terms of texture.
The intense spider web marbling is perfect for long, low heat, slow cooking techniques that allow for the fat to melt and render, which thereby tenderizes the remaining muscle flesh. On the other hand, the meat is tender enough that you can also quickly sear it with high, dry heat in a pan and slice on the bias once it hits medium rare. Perfect for sliced and plated steak dishes, or even fajitas.
I’ve tried this cut at The Pines in Brooklyn, where they sous vide the steak for many hours to render out all that flecked marbling. Once it tenderizes, they sear it hot and hard to get a good crust on the outside. Finally, they slice it up and shave some horseradish on top.
I highly recommend trying this cut of beef if you see it in the grocery store or on a restaurant menu. The good thing is that it typically costs much less than other, more common cuts that you might see.