Don't you guys hate it when a recipe writer* tells you that they've created the "ultimate" recipe, only to come back a few months later to say, "Oh yeah, by ultimate, I meant almost ultimate—here's a newer, better, easier way to do it"?
Well here's a disclaimer: that's exactly what I'm going to do today. Not because I was necessarily wrong in calling my previous recipe for the "ultimate" sliders, but because the study of burgers—like any of the other important hard sciences with which it stands shoulder to shoulder—is a constantly expanding field. We are perpetually gaining new insight and better technique. So any time the word "ultimate" is used, it should be understood that it really means "ultimate, at least as far as the current knowledge of the field allows."
With that out of the way, I'd like to talk about towels, and why you should never be without one. As any fan of Douglas Adams knows, there are few things more useful in the galaxy. Of course, its most well-known function is intimidation (for any man who can hitch the length and breadth of the galaxy, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is, is clearly a man to be reckoned with), but only slightly less well-known is this: creating perfect sliders.
I would have had the same reaction a week ago: How can a towel help you cook burgers? Let's start with a recap of the definition of a perfect slider:
Weighing in at under two ounces, the diminutive sandwiches are made by slowly steam-griddling thin, all-beef patties on a bed of onions. The aromatic steam from the onions wafts through and around the beef and buns, which are placed directly on top of the patty as it cooks. When fully steamed through,the buns become mere wisps of moist pillowy bread—the physical manifestation of sweet, pungent onion vapor. Topped with melty American cheese and a couple slices of pickle, it's the cheeseburger in one of its purest, most noble forms and as a genre, is completely unimprovable.
Well, sometimes inspiration comes when you're least expecting it, as was the case last weekend when I found myself at the Michigan Avenue branch of Telway (map) along a strip that houses equal parts strip clubs and Lebanese restaurants. The Detroit mini-burger chain serves sliders that are relatively unexceptional save two features. The first is that they are extraordinarily cheap: $0.75 if you sit at the counter, or $2.25 for a sack of four if you get them to go, making them a steal even by Detroit standards. The second is their buns. While the beef itself is lacking in flavor and texture (in a generally inoffensive way), and the onions are not as sweetly caramelized as I like in a good slider, the buns are the softest, moistest, and most aromatically onion-infused that I've had anywhere.
As soon as I tasted them, I realized that here was a way to bring "ultimate" to a whole new level.
While I'm not one to throw around the word "sassy" lightly (or even at all) it's the only way to describe the, well, the sassy ladies who man the stainless steel counter and cast iron griddle at the Telway. Once you get past the amusing attitude though, you quickly discover that these women know how to sling meat and are more than happy to show you how its done.
The burgers start off like any other classic slider. The grill-lady places a grid of small pucks of raw beef directly on a moderately hot and well-seasoned cast iron griddle before blanketing them with an insane amount of thinly sliced onions. Next she sprinkles on a healthy dose of seasoning from an unmarked can (when I pressed her to tell me what was in it, she replied "it's a secret," which I've discovered is international mom & pop restaurant code for "it's Lawry's.").
The burgers then get flipped so that they are resting on their onions, which slowly caramelize and steam as she places the buns on top. Now normally, the action stops right there, save for the last few moments when the burgers get cheesed and the assembled. But at the Telway, the key step comes next: A folded towel is placed directly over the steaming buns.
Like pockets or underwear, this is one of those ideas that when you look at it, it's so completely simple, obvious, and yet ingenious that you wonder why you've never seen it before, and why you haven't been using it for your entire life. As soon as I got home, I gave it a shot, updating the Telway cooking method with a few tweaks of my own.
First, although I've previously advocated using onion juice to maximize onion steam flavor in your burgers, my immediate thought was that with this new technique, perhaps the cumbersome step of juicing or grating onions might be rendered superfluous. Trying out a sample batch with nothing more than onions thinly sliced on a plastic mandoline and a modified version of my own Blue Label Burger Blend made with short rib instead of oxtail confirmed this: There was no shortage of onion vapor in those buns. The folded IKEA towel that I placed directly over the burgers as they cooked made sure of that.
Of course, after cooking a single batch of sliders, you're left with a skillet-full of beautifully browned sweet, savory, beefy onion bits, which make your second batch of sliders infinitely more flavorful than the first. So how does one get that sweet onion flavor from the very first batch? Simple: just brown a batch of onions in the skillet before laying down your meat.
By first caramelizing onions in the skillet and removing them, you build up a patina of sticky, browned onion juice that fuses itself to the beef when you smash the patties into it. As for the cooked onion you're left with, I just mix it together with the remaining raw onions that get smashed into the patties as they cook. In the end, it actually creates an even better onion flavor, as you get onions that hit the whole spectrum from deep, dark brown and completely melted, to only slightly wilted and still a bit crunchy.
One note: Do be aware that once you commit a towel to this process, there's no going back. It's going to be your onion-burger towel for life. This is a good thing to bear in mind before you decide to use the towel that you use to hide from the Ravenous Bugblatter Beast of Traal**, or the towel your wife dries her face with***. Onion breath is one thing to deal with—onion face is something entirely different.
**An animal so mind-bogglingly stupid that it thinks if you can't see it, it can't see you.
***Who I've discovered, looks and behaves much like a significantly more intelligent version of the Ravenous Bugblatter Beast of Traal when she discovers her towel smells like onions.