Salmon fishing is part of the Irish identity and so is this celebrated potato and kale dish known as colcannon. Let them be paired in perfect harmony for this terrific one-dish meal. Pan roasting is a restaurant-style, two-step technique worth mastering. The skin side of the salmon fillet is browned in a cast-iron frying pan on top of the stove and then quickly moved to a hot oven to finish cooking. What this high-heat roasting technique delivers is beautifully seared and deliciously crisp salmon skin with perfectly moist, flaky flesh.
Serves 6
6 center-cut salmon fillets, about 6 oz [170 g] each, skin on and scaled, pin bones removed, skin-dried (see page 40)
2 lb [910 g] russet or other floury potatoes
Fine sea salt
7 Tbsp [100 g] unsalted butter
2 to 3 cups [50 to 75 g] lightly packed chopped kale leaves
11/4 cups [300 ml] milk
4 green onions, green tops only, minced
Freshly ground black pepper
1/3 cup [40 g] Wondra (see Cook’s Note, page 76) or white rice flour
3 Tbsp grapeseed or other neutral oil
1 lemon, halved and seeded
2 Tbsp chopped fresh dill
1Remove the salmon from the refrigerator 30 minutes before cooking to bring it to room temperature.
2Position a rack in the center of the oven and preheat the oven to 450°F [230°C].
3Put the potatoes in a large pot and add water to cover by at least 1 in [2.5 cm]. Add 2 tsp salt, place over high heat, and bring to a boil. Lower the heat to a simmer, cover partially, and cook the potatoes until very tender when pierced with a fork, about 30 minutes.
4Meanwhile, in a large sauté pan, warm 4 Tbsp [55 g] of the butter over medium-high heat. Add the kale and cook, stirring frequently, until wilted, about 5 minutes. Set aside.
5In a medium saucepan, heat the milk just until hot but not boiling. Add 2 Tbsp of the butter and the green onions and simmer for 2 minutes. Add the kale, using a heat-resistant rubber spatula to scrape any excess butter from the sauté pan into the milk mixture. Stir well to combine, remove from the heat, cover, and keep warm.
6When the potatoes are ready, drain them in a colander and let stand until just cool enough to handle, about 10 minutes. Use a paring knife to slip off the skins and then return the potatoes to the pan. Mash with a potato masher. Stir the milk mixture into the potatoes and mash to distribute the kale evenly. Season with salt and pepper. Keep warm while you prepare and cook the salmon.
7Blot the salmon dry with paper towels. Season both sides of each salmon fillet with salt and pepper. Spread the flour in a pie plate or a wide, shallow bowl. Dip the skin side of each fillet in the flour, shaking off the excess. As the fillets are coated, set them aside, coated-side up, on a plate.
8Place a large ovenproof frying pan, preferably cast iron, over medium-high heat. When the pan is hot, add the grapeseed oil and swirl to coat the bottom of the pan. When the oil is hot but not smoking, add the salmon fillets, skin-side down, then press down on each fillet with the back of a metal spatula to maximize the contact with the surface of the pan. (This helps crisp the skin.) Cook on one side, without disturbing, until the skin is golden and crisp, about 3 minutes. Turn the fillets skin-side up and transfer the frying pan to the oven. Roast the salmon until almost opaque throughout but still very moist, or an instant-read thermometer inserted into the center registers 115° to 120°F [45° to 49°C], 3 to 4 minutes longer.
9Melt the remaining 1 Tbsp butter. Divide the potato mixture evenly among warmed dinner plates, mounding it in the center. Place a salmon fillet, skin-side up, on top of each mound. Drizzle a little butter over each portion of salmon and potatoes. Squeeze some lemon juice on top and garnish with the dill. Serve immediately.