For any student of the cuisines of the world, words like mirepoix, soffritto, and Holy Trinity are well known—they all describe the aromatic flavor bases of French, Italian, and Cajun cooking, respectively. But I'm going to go out on a limb and wager that for most well-versed cooks, the word kroueng still doesn't mean all that much. So what is it? Kroueng is the name of a wide variety of aromatic flavor bases used in Khmer cooking, which I'm familiar with through my mother-in-law, who is Chinese-Cambodian.
Of all the dishes she makes, one of my favorites is Sach Ko Jakak, which simply means "beef stick." But oh, it is way more than just a beef stick, and what makes it so special is the kroueng she makes to flavor it. Her recipe uses a pounded mixture of makrut lime leaves, turmeric, galangal, and lemongrass. Whenever there's a family barbecue, this dish is my number-one request.
When I was trying to recreate my mother-in-law's kroueng recipe to share with you all, the main thing I wanted to figure out was how to make a version that tasted right, but didn't rely on a lot of hard-to-find ingredients. Living in Philadelphia, I can track down most of the things required, though even I run into trouble with some of them, like the fresh lime leaves and fresh turmeric. In smaller cities and towns, finding them can be next to impossible. The question was: what could I use in place of those more obscure ingredients that would capture the flavor of the original dish?
I started off by thinking of the way all those aromatics combine to create an overall flavor, which can be hard to pinpoint. Lemongrass and makrut lime leaves bring a hint of bright citrus flavor, fresh galangal (which is part of the ginger family) adds a pungent, earthy fresh ginger taste, and turmeric root adds a mild bitterness.
Replacing one ingredient with another can be tricky: Substituting dried herbs for fresh ones doesn't always work, for example. Often, the trick to capturing the flavor of one ingredient involves combining several others. Of course a perfect facsimile is next to impossible, but I'm pretty happy with what I've come up with here. More importantly, my mother-in-law is too.
To make my version of the paste, I combine chopped fresh lemongrass and bay leaves, thyme, lemon zest, lime zest, ginger, and crushed garlic in a mortar and pestle—the best way to release the aromatic flavors of the ingredients, though of course a food processor will work if that's all you have. I pound everything together, crushing it into smaller and smaller pieces until a coarse paste forms.
Next, I add turmeric powder, lemon juice, salt, sugar, and cinnamon, then pound again until everything is mixed together.
You can make the paste up to a few days ahead, and then all that's left to do is slice the beef, rub it with the paste, and slide it onto skewers. I use sirloin or flank steak that I've sliced into strips about 1/8 inch thick.
They don't take long to cook over direct heat on the grill, only 2 to 3 minutes on each side.
They're best served hot, maybe with a side of cabbage salad tossed in a spicy fish sauce-and-lime dressing.