Place the orange juice, orange zest, shallot, olive oil, vinegar, dijon mustard, and kosher salt in a blender. Blend on high until the mixture looks creamy and the shallot is incorporated, about 20 seconds.

Place the walnuts in a small sauté pan over medium heat. Cook, shaking the pan occasionally, until the walnuts are fragrant and toasted, about 3–4 minutes. Watch carefully so that they do not burn.

Place the arugula and mixed greens in a large bowl. Pour half of the dressing over the top and toss gently with salad tongs or clean hands. Taste and add more dressing if desired.

Transfer the greens to a large platter. Top with the walnuts and pomegranate arils. Season lightly with additional kosher salt, and serve immediately.