In a large bowl, whisk together the Dijon, olive oil, and lemon juice. Add a pinch each salt and pepper. Mix in the orzo and walnuts. At this point, let the pasta cool a bit if necessary so the greens don't wilt. Taste for seasoning (will need a bit more, like ~1/4 t or more). Gently toss in the salmon, greens, and pomegranate seeds. Serve warm or chilled. Yield: 5 servings.