1. Combine mayonnaise, yogurt, scallions, lemon juice, and dill.
2. Season salmon with salt and pepper. Heat oil in a large nonstick skillet over medium-high heat. Add salmon, flesh-side down, and sear 3 minutes, until brown. Flip and sear another 3 minutes, until salmon is just cooked through.
3. Place a dollop of sauce on serving plate; top with salmon and a small mound of sprouts.