Pat scallops dry with paper towels; sprinkle with salt and pepper. In a large skillet, heat 2 tablespoons oil over medium-high heat. Add scallops; sear 1-2 minutes on each side or until golden brown and firm. Remove from pan; keep warm.
In same pan, combine chives, vinegar, garlic, tarragon, honey, mustard and remaining oil. Bring to a boil; cook and stir until slightly thickened, about 30 seconds.
Divide greens, carrots and tomato among four plates; top with scallops. Drizzle with dressing; serve immediately.