Served with rutabaga purée and braised red Russian kale, this wahoo recipe is a complete and balanced dinner for four. Wahoo, also known as ono, is a fish found off the coast of Hawaii and also in the Caribbean, and has a firm white flesh with mild flavor.
Combine all of the ingredients in a mixing bowl and let the flavors meld for 1 hour prior to serving.
Place the potatoes and rutabaga in a large pot of salted water and bring to a boil. Cook until very tender, for about 45 minutes. Drain well, transfer to a food mill, and purée until smooth. Return the puréed mixture to the pot and stir over medium heat until any excess liquid evaporates. Add the butter and stir until melted. Season with salt and pepper, to taste.
In a sauté pan, heat the olive oil over medium heat. Sauté the onion and garlic until the onion becomes soft. Add the kale, wine, and broth. Toss, then simmer gently until the kale is lightly cooked, for 15 minutes. Season with salt and pepper, to taste.
Heat the oil in a cast-iron skillet or heavy-bottomed sauté pan over medium-high heat. Swirl it around to coat lightly.
Dust the wahoo medallions with blackening seasoning, to taste, and then place them in a single layer in the pan. Sear the medallions until the bottom changes to a light brown color. Flip the medallions and reduce the heat to medium. Cook until the other side turns light brown and the center of the fish is opaque.
Set out 4 plates. On each plate, place a scoop of the potato-rutabaga purée, ½ cup of the kale, and 2 wahoo medallions on top in the center. Drizzle 2 tablespoons of the tomato-caper vinaigrette on top of the fish, allowing some to drip down the sides of the wahoo medallions onto the rutabaga purée and kale.