Ingredients
4 skin-on salmon fillets (each about 6 ounces), preferably Wild Alaskan
Kosher salt and freshly ground white pepper
2 tablespoons unsalted butter
1 tablespoon extra-virgin olive oil
2 shallots, finely chopped (1 cup)
1 celery stalk, cut into a 1/4-inch dice (1/2 cup)
1 small fennel bulb, cored and cut into a 1/4-inch dice (1 cup), plus tender fronds for serving
6 ounces cremini mushrooms, halved or quartered if large (1 1/2 cups)
4 teaspoons unbleached all-purpose flour
1/2 cup dry white wine, such as Sauvignon Blanc
2 bottles (each 8 ounces) clam juice, or 2 cups fish stock, such as Bar Harbor
2 tarragon sprigs, plus picked leaves, sliced if large, for serving
1 small dried bay leaf, or half a large leaf
2 large egg yolks, room temperature
1/4 cup heavy cream, room temperature
2 tablespoons fresh lemon juice
Cooked white rice or crusty bread, for serving
Preparation
Season salmon with salt and pepper. Heat a large straight-sided skillet or wide, shallow pot over medium-high; add 1 tablespoon butter and oil. When foam subsides, add salmon, skin-sides down. Cook, undisturbed, until skin is crisp and fish turns opaque halfway up sides, about 5 minutes (if butter begins to brown, lower heat). Transfer salmon to a plate, skin-sides up.
Reduce heat to medium-low; add shallots, celery, fennel, and mushrooms, scraping up any browned bits from bottom of skillet; season with salt and pepper. Sauté, stirring occasionally, until vegetables soften but don’t develop color and mushrooms become glossy, 7 to 9 minutes. Stir in flour; cook 1 minute. Add wine and bring to a boil, stirring constantly, until liquid just thickens, about 30 seconds. Add clam juice, tarragon sprigs, and bay leaf. Bring to a simmer, then partially cover, reduce heat to medium-low, and simmer 10 minutes.
Return salmon to skillet, skin-sides up, along with any accumulated juices. Partially cover and continue simmering until just cooked through, 4 to 5 minutes. Transfer salmon to a plate; remove and discard herbs.
In a small bowl, whisk together egg yolks and cream. Slowly pour in 1/2 cup cooking liquid, whisking constantly. Stir cream mixture into skillet. Add remaining 1 tablespoon butter and lemon juice, stirring until butter melts. Return salmon, skin-sides up, and any accumulated juices to skillet; simmer, uncovered, 30 seconds. Top with tarragon leaves and fennel fronds and serve with rice or bread.
