Preheat oven to 375 degrees F.

Place salmon fillets on a baking sheet lined with foil. Brush the tops of salmon with Dijon mustard and sprinkle with “everything bagel” seasoning generously and evenly.

Bake until salmon is flaky, firm, and reaches an internal temperature of 145 degrees F, about 8 – 12 minutes.

Remove from oven and set aside.

While the salmon is baking, prepare the vinaigrette. Combine capers, minced shallot, and lemon juice in a mixing bowl. Drizzle in olive oil and whisk briskly until oil and lemon juice are fully combined. Slowly drizzling oil into lemon juice while whisking briskly yields a temporary suspension, or emulsion, which creates a creamy vinaigrette. Season to taste with salt and pepper.

In a small bowl, whisk together sour cream and chives. Season to taste with salt.

Add arugula to the bowl containing the lemon-caper vinaigrette and toss gently.

Place a bed of dressed arugula in the center of the plate. Top with halved tomatoes, sliced shallot, and salmon. Add a dollop of chive sour cream on the salmon, garnish with lemon zest, and enjoy!