Over the years of playing around in my kitchen I’ve learned a few advanced techniques, all self-taught so probably not executed that well…but well enough. I can reverse-sear a rib eye steak to a textbook medium rare each and everytime I cook steak. I give it a few hours at a precise temperature of 132 degrees in my sous vide cooker, finishing it off on my grill for that nice tasty Maillard crust. When I’m grilling steak for guests I will sometimes plate that fork tender steak with perfectly formed horseradish pearls using molecular gastronomy and a carefully measured amount of agar-agar. That’s a melt in your mouth bite of beef followed by the sharp pop of heat from an exploding horseradish pearl that will bring tears to the eyes of any beef lover. And not from the horseradish.
My most recent love affair with a dish was a sweet onion marmalade I encountered about this time last year in Santa Barbara. One of the places Janet and I stopped at for a meal was Chef Cat Cora’s laid-back Mesa Burger in Goleta, and I had the most delectable lamb slider with a sinfully good sweet onion marmalade. Right then and there I decided I was going to make that marmalade in my own kitchen. Some day.
My going in thought was how tough could it be? It was a condiment after all, and condiments are an afterthought. Do you prefer ketchup, mustard, or mayo with your burger? Yes, please. Some people like lettuce, tomato, pickles, and even raw onions on their burger…some people don’t. I’m OK with all those. Except the raw onion. It hijacks my tastebuds. My point is when you serve up a burger, as a cook you don’t give much thought to what goes on it, or next to it. Unless you are a kick-ass Iron Chef like Cat Cora. There are no afterthoughts on any of her dishes…everything on the plate contributes to the overall flavor palate the dish is engineered to deliver, and is meant to be consumed. Even the garnishes and condiments, and especially the onion marmalade. I could have made a meal out of it, and that’s why I deemed it copy worthy.
In my onion naivete, I wasn’t overly concerned with cooking the onions. Who can’t cook up a skillet of onions? Well…me, apparently. I ruined an embarrassing number of onions in my attempts to prefect this dish. My chief concern was how to recreate that tasty goo Chef Cora bathed them in. I had no idea what went into it. I figured it would take quite a bit of experimentation to get it right, but little did I know the goo would turn out to be the easy part.
The trick with this dish is that it involves applying two different browning processes to the onions that are complementary while at the same time work in competition with each other: caramelization and the Maillard reaction. I’ll skip the science behind it and just say the only way to get caramelized onions that are sweet while at the same time savory, nicely browned, complex in flavor and not burnt is to go slow over medium-low heat. Which means it takes time…way more time than you think, and you can’t cheat the process with hacks. I know because I tried all the hacks I could find.
Before I delve into what works, I have to say a bit about what doesn’t work. The hacks. Don’t do it. Whether it is adding baking soda or table sugar to the skillet, don’t do it. Enough said.
On the surface this is a simple recipe that doesn’t require any fancy technique, but it does require skill. And patience. Lots of patience. It only takes a couple of ingredients…some onions, butter, oil (optional) and about a cup of water or broth…I chose beef broth. That’s it. It doesn’t even matter what kind of onion you use…I went with candy onions because that’s what the local farm stand had in abundance when I decided it was time to try recreating Chef Cora’s marmalade.
What elevates this simple condiment to Iron Chef level is what you do with those ingredients, and I discovered I needed to do three things for this recipe to work. I needed to caramelize the onions, which uses heat to break down the sucrose in onions into simple sugars…fructose and glucose. The simple sugars register more readily on the sweetness receptors in your taste buds and caramelizing is what makes that happen. But I also wanted the rich, savory complexity you get with Maillard browning, which occurs when some of the liberated glucose recombines at a molecular level with amino acids in the onion proteins to form hundreds of new and richly flavorful compounds. Anyone who grills understands the Maillard reaction, even if only intuitively. It’s what gives a nicely grilled steak that delectable tasting crust.
Heat is what you need for both caramelization and the Maillard reaction, and both reactions occur naturally when you cook up a batch of onions in a cast iron skillet over medium low heat. The trick is to resist trying to speed things up by using a higher temperature setting. Onions will burn in the blink of an eye if you apply too much heat. Low and slow is the way to go for this dish. Plan on at least an hour of cook time to get it right, stirring regularly to make sure nothing burns. It only takes a few bits of burnt onion to ruin the entire batch. I know. I ruined plenty of batches trying to get this recipe down.
The third thing I needed was something to form a gel for the onions to set in. Otherwise, it would just be a batch of cooked onions…great on any meat dish, but it was the marmalade treatment that elevated Chef Cora’s onion condiment to new heights of culinary excess.
I stumbled on how to make a marmalade gel for this dish even before I perfected my technique for caramelizing the onions. Mostly because I unabashedly tried to cheat. I tried one of the “time saving” hacks I found on the internet for making caramelized onions…using a pressure cooker. In my defense, I found it on my go-to site for food science, Serious Eats. Their Food Lab scientists presented the pressure cooker hack as a cheat to cut down on the time necessary to caramelize onions, but in the end it didn’t work. It rendered the onions down to a soupy consistency where the onions lost all structural integrity. And though that isn’t what you want when making caramelized onions, it works great for making the base of a French onion soup. And, as it turns out, the base for a sweet onion marmalade, or as I call it…the goo.
The prep for this dish was simple. I cut my onion in half, dicing one half to use in my Instant Pot for the goo, and cutting the other half into slices to cook up in the skillet. I set the Instant Pot to sauté mode, tossed in a tablespoon of unsalted butter, and after that melted I added the diced onion. I cooked the onion dices up just to the point of rendering out some of the liquid, added a cup of beef broth, and then put the lid on and switched to pressure cooker mode. I set the timer for 20 minutes and let the Instant Pot do its thing. I skipped the Serious Eats step of adding baking soda. I understand the science behind it, but it also leaves an unpleasant chemical aftertaste. No thanks.
When the Instant Pot timer was down to just a few minutes remaining, I put my cast iron skillet on the cooktop and set the temp to medium high just long enough to get it hot, then turned it down to medium low. You can add a bit of oil to the skillet if you want, but I chose not to. When the pressure cooker timer beeped, I released the pressure and poured the contents into the cast iron skillet, gave it a few stirs, then added the onion slices.
At that point it was a simple matter of babysitting the onion slices as the heat did its thing, stirring them occasionally to make sure nothing burned. I fiddled with the temperature setting throughout the cooking to avoid burning anything. The low and slow cooking also further reduced the liquid from the contents of my Instant Pot into more of a gelatinous goo, which is what I needed for this to be a proper marmalade.
How do you know when it’s done? When the onions are nicely brown, taste sweet and complex, most of the liquid in the goo has rendered out, and your arm gets tired of stirring. For me, I wanted onions that were limp but with enough structure to be identifiable as onions. It took about an hour and 15 minutes of steady stirring over a medium low heat to get the results I was aiming for. And quite a bit of stirring. That’s in addition to the time it took to make the goo in my Instant Pot. Figure on at least 90 minutes from start to finish, and it can take even longer if your onions are particularly juicy.
My sweet onion marmalade was delicious. I served it with some beef sliders I cooked up on my grill, the beef of course coming from my favorite source, Roseda Farms. The marmalade turned out oh so sweet and savory with a richly complex flavor profile. The combination of the fatty beef flavor of the sliders and the onion marmalade was a pairing that worked better than I hoped. I doesn’t taste quite the same as my memory tells me I got from Mesa Burger…it tastes better. But I am biased. In any event, this condiment has earned a spot in my arsenal of ways to impress my guests the next time I go for a casual dinner of burgers on the grill. It keeps well in the fridge too and reheats nicely with a short stint in the microwave. Now all I have to do is cook up another batch with the same results so I know it wasn’t a fluke.
Thank you, Chef Cora!