Sunny-Side Up Lentil Salad

Boil 3 cups water, tomatoes, onion, lentils, celery, carrot and thyme in a medium saucepan. Reduce heat to medium-low; simmer until lentils are tender, 20 to 25 minutes. Drain; reserve cooking liquid. Return liquid to pan; boil over high heat to reduce liquid to 1/4 cup. Add 2 tablespoons vinegar and lentil mixture to liquid; stir over medium heat. Add 1 tbsp tarragon; season with salt and pepper. Remove from heat but keep warm. Whisk remaining 1 ⁄2 tbsp vinegar in a bowl with mustard and oil; add salt and pepper. Coat a medium skillet with cooking spray; set over medium heat. Carefully add eggs so yolks remain whole; cook until whites are set; add salt and pepper. Toss lettuces with mustard dressing; divide evenly among 4 plates. Top greens with 1/4 lentils and 1 egg each; sprinkle with remaining 1 tablespoon tarragon.