Achar is a tableside condiment you’ll find in many Indian households—it’s a combo of fruits and/or vegetables pickled in oil and spices, and it’s eaten alongside rice, dal, sabzi, or really anything that could use some salt and complexity. My mom’s youngest brother, Sharad, smartly realized that achar and the accompanying spice-infused oil at the bottom of the jar make an excellent marinade for amping up a simple white fish—no measuring or spice blending required. After testing a bunch of different kinds of bottled achars (you can make homemade achar, but honestly, who has the time or patience), he settled on mango for its tangy depths and sweet-and-spicy overtones. But the real genius of this dish comes in cooking rings of red onion in the residual achar oil, then serving them atop the fish—they make for a beautiful, crunchy, slightly charred and caramel-y counterpart. Try these wrapped up in fish tacos! And if you ain’t a fish person, you can use the achar marinade on chicken or cauliflower.
Serves 4
1 Pour the achar (making sure to get some of the oil) into a large resealable bag. Add the fish fillets, seal the bag tightly, and use your hands to gently massage the achar onto the fish, fully coating the fillets. Refrigerate for at least 20 minutes, or up to 2 hours.
2 In a large skillet (one that will fit all 4 fillets) over medium-high heat, warm 4 teaspoons of the oil (if your skillet is too small, you can do this in two batches—just divide the oil). Once the oil begins to shimmer, add the fish fillets and sprinkle the top of each with a small pinch of salt (or to taste; see Tip, below). Cook the fish for 3 to 5 minutes, until the fillets are golden on the underside and the top is starting to flake, then flip. Sprinkle with a pinch of salt, if desired, and cook for 2 to 3 minutes on the second side—again, you should see flaking on top. Transfer the fish to a plate and return the skillet to the stove.
3 In the same skillet over medium-high heat, warm the remaining ¼ cup oil. Once the oil begins to shimmer, add the onion rings and cook until soft and translucent, 5 to 8 minutes—or longer, if you like them more caramelized.
4 Top the fish with the onion rings.
tip: Taste the achar before cooking to gauge its saltiness; this will help you determine how much salt to add.