salmon fillets, skin removed
kosher salt and black pepper
unsalted butter, cold
small shallot, finely chopped
roughly chopped fresh dill, plus more for serving
cucumber, thinly sliced (optional)
- Set broiler on high. Place the salmon on a foil-lined broiler pan, season with ¼ teaspoon salt, and broil until it is the same color throughout and flakes easily, 7 to 10 minutes, depending on thickness.
- Meanwhile, in a saucepan, over medium-high heat, heat the oil and 1 tablespoon butter until it melts. Add the shallot and cook until soft, about 1 minute.
- Add the wine and cook until reduced by half, about 3 minutes.
- Reduce heat to low and whisk in the mustard, dill, ¼ teaspoon salt, and ⅛ teaspoon pepper. Remove from heat.
- Cut the remaining 2 tablespoons butter into pieces, add to the sauce, and whisk until incorporated.
- Place the salmon on individual plates, spoon the sauce over top, and sprinkle with additional dill. Serve with the cucumber slices (if desired).