I peeled and crushed a bunch of garlic, and coarsely chopped a bunch of cilantro.
Tossed them over the steaks in a plastic container.
I added 1/2 cup of lime juice then 1/2 cup of olive oil, then I decided it was too much oil so I added more lime juice. As you can tell, this was a scientific method and a very very strict recipe.
Tonight I marinated the steaks for about 3 hours, turning once. When it was time to cook the steaks, I heated olive oil in a cast iron pan over medium-high heat until the oil shimmered, seasoned the steak with salt and pepper, and added to the pan. 4 minutes on each side. Steve's was quite a bit thicker, so I ended up at 5 1/2 minutes on each side for his.
Flat irons can be tough, and really benefit from the shorter cooking time and resting after coming off the heat. I could have probably gone 10 minutes, but I only let it rest 5 this time. I was hungry.
Thin slices against the grain, and served with chilled carrot and honey soup.