A smoking hot cast iron skillet is the best way to put a good crust on a fat burger like this.
Dry Age Trim
The trim from several aged prime rib roasts went into making these burgers. The trim ranged form between 21 to 61 days. I froze it all in cryovacked bags as I collected it, then thawed it out in the fridge over the course of two days when I was ready to grind.
Ready to Grind
The beef, trimmed, chunked, and ready to grind. Notice that fat? That's where most of the dry aged flavor comes in.
If everything is chilled, the meat should grind very nicely, coming out in distinct strands like this, rather than solid mush, which can happen if sinew or smeared fat clogs up the blades. I grind at medium speed.
To get the last bits of meat out, press a piece of paper towel down into the feed tube. It'll push out the meat without getting ground itself.
Spread the meat across a rimmed baking sheet lined with foil. The goal here is to keep it as loose as possible.
Press the meat into cohesive patties, pressing just until they hold together on their own, allowing them to stay as loose as possible without actually falling apart.
Season the patties well on both sides with salt and pepper.
Get 'er Ripping
Heat up a touch of oil in a cast iron skillet over high heat until it starts smoking.
Flip and Keep Cooking
You can flip your burger as many times as you want, or just flip it once if you're that kind of person. Either way, the goal is to develop a deep, crisp crust.
Once a good amount of fat has rendered, you can start basting the burger with a spoon, which will help it crisp better and cook faster from both sides.
Take the temperature. For a nice medium rare, I go for around 115 to 120°F (a little lower than for a steak, as the air spaces in a burger allow it to carry over a little more than a steak does).
Place a slice of cheese on top to get it started melting.
I like to use the rendered beef fat to quick-fry some onions. We're not really caramelizing here so much as softening and lightly charring.
See how nice and brown/frizzled they get?
I spread some Thousand Island-style spread on the top and bottom of the toasted bun.
Flash the Beef
Flash the burger under the broiler just to melt the cheese.
Now THAT'S a burger.