Have Leftover Salsa? Make Baja Sauce

There's a trio of family-owned Mexican restaurants on Chicago's North Side that sell some of the best tacos in the city: Taqueria El Asadero, Taqueria 5 De Mayo, and the newest addition, Taqueria Las Flores. Anthony Bourdain even made a trip to Asadero (the original location, open since 1993) during the Chicago episode of The Layover in 2012, and there's a sense of collective relief each time a new sister restaurant opens and it's confirmed to be as delicious as the original.

The carne asada in particular is a draw. "When cut too thick, the meat can often end up chewy and greasy," writes Chicago Tribune dining reporter Nick Kindelsperger, "But the thin shards here are nicely caramelized and tender—a tough sweet spot to find." Another bright spot is an item that dine-in customers never even have to pay for: the complementary tortilla chips. Kindselperger describes them as "absolutely stunning," and I agree: airy, crispy, greasy, and salty, they're the very best in the city and perhaps on the planet.

Something that elevates every order on the Asadero menu is the salsas, both verde and roja, which are set down on the table in squeeze bottles so massive, they almost require two hands to operate. Both salsas are thin and have the perfect amount of bite—or rather, it's perfect these days. My palate spent years trying to catch up to, tolerate, and ultimately crave the spicy heat of these condiments. I'd go so far as to credit Asadero with unlocking a whole new world of culinary discovery for me, a person who thought she "couldn't handle" spice until the right dish came along to make those spices sing.

With no current dine-in operation available, my husband and I have been ordering pickup at Las Flores, and—bless them—they don't skimp one iota on the salsas. At a ratio of about one tub per taco, we're gifted bags full of red and green salsa cups, which means we're left with quite a few after polishing off our meal. These can be used to top scrambled eggs or whipped into makeshift Chipotle bowls with some shredded chicken, but the best application we've found is by turning them into what we're calling, for lack of a better term, baja sauce. Its applications are wide-ranging, and the creaminess of the added yogurt softens the spiciness just enough to apply the sauce liberally without feeling like our mouths are on fire. Meanwhile, a kick of vinegar keeps it properly acidic to balance out the fatty flavors in a dish. It's also a great way to use up the last bit of store-bought spicy salsa, the half-inch or so that sits on the bottom of the container, insufficient for chip-dipping. To save on dishes, you can mix this sauce together right inside the jar. Go forth and breathe new life into your leftovers—and maybe come up with a more clever name while you're at it.

Marnie Shure

• 2-4 oz. salsa (whatever type you've got)
• 3-5 Tbsp. Greek yogurt (I've used Fage 2% and Siggi's 4%)
• 1-2 tsp. white vinegar or lime juice

Whisk all ingredients together, incorporating 1 tablespoon of yogurt at a time until the sauce has the desired thickness. Use as a sauce on fish tacos. Or combine it with some shredded red cabbage, shredded carrots, and diced jalapeno for a zesty slaw. Or pour over a serving of crispy potatoes. Or serve straight up in a ramekin and use as a dip for airy, crispy, greasy, salty tortilla chips.