The Flat Iron Steak, aka the Top Blade Steak, is the end of the chuck. It was developed in university labs, which is incredibly cool to those of us food geeks who find the science of food as appealing as its nutritive and flavor qualities. The reason for laboratory development was because they took the genes of the best tasting. . . . OK, no, that's wrong.
The reason that it took teams in two major United States universities to develop the flat iron steak is because, sitting at the end of the Chuck where it does, it has a chunk of connective tissue in the middle of three pieces of succulently tender and flavorful beef that had to be navigated around. They took this garbage cut of meat and cut it in such a way that it got rid of the leathery connective tissue, leaving only the beautifully marbled, tender and delicious beef.
Locally, this is still a pretty cheap cut of beef, comparable to the Top Sirloin, but the flavor is incomparable. I have waited for years to try this cut, and now I want to try it in every way possible. When in Gardnerville, Nevada last time, at a little Basque restaurant, I had a garlic steak. They used a shell steak, but I think that I am going to try this with a nice thick Flat Iron.