One skillet. One burner. One fillet. "That's the simplest approach," says Kinch, "and it takes only a few minutes." But, as with everything worthwhile, the devil is in the details — like how to get the skin perfectly crisp but leave the flesh moist, tender, and flaky. Kinch showed us, and he threw in a classic accompaniment — a Catalan-style spinach, whose preparation can act as a template for any improvised vegetable side. Kinch recommends skin-on fillets because of the textural contrast crunchy skin provides, and because "the skin is one more barrier between the flesh and the heat, so you don't overcook the fish, and you hold on to more moisture." But the basic technique also applies to skinless fillets. Simply designate one side for presentation and start the process with it facing down. As for exact species, it could be sole, halibut, bass, cod — "just about anything firm, white-fleshed, and low in fat content," Kinch says.
2 6-oz fillets of black cod, skin on
Canola oil For the Catalan
Spinach: 2 tbsp golden raisins
6 tbsp brandy
2 bunches whole-leaf spinach
2 tbsp pine nuts
2 oz prosciutto
1. Get the fish dry Before you start, blot the fish all over with paper towels. This removes excess water that could leak into the pan and make the fish steam instead of sear. Also, do not salt the fish before cooking: Salt draws out moisture — those droplets will drip down the sides and create steam, too.
2. Brown the skin Place a pan over medium heat. After about a minute, add a thin film of oil. Then place fish in the pan, skin side down. "Hear that nice sizzling sound?" Kinch asks. "But no spitting or popping." (That means your pan is too hot.) Fish skin contracts in response to heat, causing the fillet to curl. To prevent this, press gently on the fillet with a spatula or — Kinch's preferred method — set some kind of weight, like a brick, plate, or plancha press (see below), on top for 45 seconds. Don't move the fish: It will almost always stick to the pan at first; if you try to release it with a spatula, you'll shred it. But once all the water cooks out of the skin, it'll release itself from the pan.
3. Look closely Raw fish is translucent; cooked fish is opaque. To gauge the doneness of any fillet, look carefully at its sides. That line of opaqueness will be moving steadily upward from the pan toward the top of the fish. Once that line hits two-thirds of the way up, salt the top side of the fish and flip it over.
4. Give it a poke A thin metal rod — Kinch prefers a cake tester, but you can use any meat thermometer or metal BBQ skewer — allows you to gauge doneness in two ways. First, insert the rod into the thickest part of the fillet. If the tip meets resistance, the fish isn't cooked. Second, leave the rod in the fish for five seconds, and then pull it out and touch it to your upper lip. If the metal feels at all warm, the fish is cooked.
5. Prep the Catalan spinach Place raisins in a small saucepan with the brandy. Bring to a simmer and remove from heat. Strip stems from spinach. Place leaves in a skillet over medium heat, and turn gently until they wilt. Remove to a colander to drain.
6. Finish the dish Remove fish to a plate lined with a paper towel. Add the raisins and pine nuts to the fish pan; add the prosciutto, spinach, and lemon zest. Toss everything and heat through. Place fish back in the pan just long enough to warm. Serve.