In a large saucepan fitted with a steamer basket, bring 1 inch of water to a boil. Add the tomatoes, cover and steam over moderately high heat for 1 minute. In a shallow bowl, mix 3 tablespoons of the olive oil with the lemon juice. Add the tomatoes, season with salt and pepper and stir to mix.
Spread the scallops in the steamer basket. Drizzle with the remaining 1 tablespoon of olive oil and season with salt and pepper. Cover and steam over moderately high heat until just cooked, about 5 minutes. Transfer the scallops to a shallow bowl and keep warm.
Add half of the spinach to the steamer, cover and steam for 2 minutes; stir. Add the remaining spinach, sprinkle with 1/2 teaspoon of salt and toss well. Cover and steam for 2 minutes.
Mound the spinach on plates. Top with the scallops and any accumulated juices and spoon the tomato vinaigrette over all. Sprinkle with the chives; serve.
One Serving 307 calories, 15.9 gm total fat, 2.3 gm saturated fat, 11 gm carb.