¼ cup sliced or slivered almonds
1 (6- to 8-ounce) skinless salmon fillet, pin bones removed
3 teaspoons Dijon mustard
Kosher salt and freshly ground black pepper
1 tablespoon red wine vinegar
2 teaspoons grated fresh or prepared horseradish
2 tablespoons extra-virgin olive oil
1 cup thinly sliced spinach leaves
1 small red or yellow beet, peeled and cut into matchsticks
½ avocado, diced
1 Preheat the oven to 350°F.
2 Arrange the almonds on a sheet pan and cook until lightly toasted, about 8 minutes. Set aside.
3 Reduce the oven temperature to 275°F. Line a sheet pan with foil.
4 Using paper towels, pat the fish dry. Evenly coat the salmon on all sides with 2 teaspoons of the mustard. Season the fillet on all sides with salt and pepper. Place the fish on the lined sheet pan and bake until the fish reaches an internal temperature of 130°F, about 20 minutes. If you prefer a flakier fish, cook for another 10 minutes.
5 In a small bowl, whisk together the vinegar, horseradish, and remaining 1 teaspoon mustard. While continuously whisking, slowly add the olive oil in a steady stream. Season with a pinch of salt and a twist of pepper. Add the spinach, beet, avocado, and almonds and toss to combine.
6 Transfer the salad to a plate, top with salmon, and serve.