Diane, Here is a recipe from Molly Katzen's cookbook, Vegetable Heaven.
"I have very few iron-clad cooking rules, but here's one I think few people would argue with: Vine-ripened tomatoes in season should be tampered with as little as possible. After all, who are we mortals to think we can improve upon perfection itself?
That said, here is a minima;ist recipe for enhancing the tomatoes' natural brillance. It calls for dressing them with a small amount of warmed, scallion-infused olive oil, then finishing the dish with a little salt and pepper. Rather than overshadowing the tomatoes, this treatment augments them beautifully.
Simplest Tomato Salad tastes best if eaten shortly after it is assembled. I like it at room temperature."

Simplest Tomato Salad

3 Tbl. olive oil
4 scallions, minced
1/2 tsp salt or to taste
Freshly ground black pepper

Simplest Tomato Salad
Yield: 4-6 servings, Preparation time: 10 minutes

Heat olive oil in a skillet over medium heat. Add the scallions, and saute for about 5 to 8 minutes, or until the scallions are completely wilted. Set aside to cool for about 5 minutes.

Meanwhile, slice tomatoes in half, squeeze out and discard the seeds. Cut the tomatoes into bite-sized chunks, and place them in a medium-sized glass or ceramic bowl.
Pour scallions and oil (still warm) over the tomatoes, and sprinkle on a little salt and a fair amount of black pepper. Stir gently and serve right away at room temperature, or cover tightly and chill.