The beloved flavor pairing of salmon and mustard gets an elegant twist with the addition of white wine and butter. Baked low and slow until meltingly tender, the fish is served with a crisp fall salad of wine-soaked dates, apple and cucumber tossed in a light mustardy vinaigrette.
For the salmon: Preheat the oven to 300 degrees F.
Brush a 9-by-13-inch baking dish with a thin coating of butter and sprinkle a little salt and pepper over the surface. Set the salmon fillets in the baking dish skinned-side down and sprinkle with salt and pepper.
Whisk together the 2 tablespoons butter, Dijon mustard, parsley, white wine, lemon juice and 1/2 teaspoon salt in a small bowl. Spoon the mixture evenly over the top of the salmon. Bake to the desired doneness, about 14 minutes for medium-rare (cook longer for thicker fillets).
For the salad: Meanwhile, bring the white wine to a boil in a small saucepan over medium-high heat. Immediately remove from the heat, stir in the dates and set aside. Whisk together the mint, Dijon mustard and lemon juice in a large bowl. Slowly whisk in the olive oil and season to taste with salt and pepper.
Wrap the cucumber in a clean kitchen towel, set on a cutting board and smash with the heel of your hand. Unwrap the cucumber and slice crosswise into 1/2-inch pieces. Add the cucumber to the bowl with the dressing and sprinkle with a little salt (don't toss with the dressing yet). Let the cucumbers sit for 5 minutes before adding the date mixture, apples and pine nuts. Toss to evenly combine. Season with salt and pepper to taste. Serve with the salmon.