Warm Grilled Tomato Salad

½ cup extra-virgin olive oil, plus more for coating the tomatoes and onion

4 large firm tomatoes (about 2½ pounds)

1 large onion, cut into ½-inch slices

2 cups fresh green beans, trimmed and blanched (see notes)

¼ cup balsamic or red wine vinegar

1 large clove garlic, minced

½ teaspoon dried tarragon

1 teaspoon Dijon-style mustard

Salt

Freshly ground black pepper

Prepare the grill for direct heat. If using a gas grill, preheat to medium-high (450 degrees). If using a charcoal grill, light the charcoal or wood briquettes; when the briquettes are ready, distribute them under the cooking area. For a medium-hot fire, you should be able to hold your hand about 6 inches above the coals for about 4 or 5 seconds. Have ready a spray water bottle for taming any flames. Lightly coat the grill rack with oil. Have a large serving bowl at hand.

Use a little oil to lightly coat the cut sides of the tomatoes and onion. Place the cut sides down on the grill rack; cook the tomatoes for about 4 minutes on each side, then transfer to the platter. (Discard any loosened skins, if desired.) Cook the onion until grill marks have formed on both sides (about 15 minutes total, turning them over as needed), then transfer to the serving bowl. Place the blanched green beans in a grill basket and grill for about 6 minutes, so that some of them have browned on the ends; transfer to the bowl. Cover loosely to keep warm.

Combine the vinegar, garlic, dried tarragon and mustard in a medium bowl. As you whisk, add the 1/2 cup of oil in a slow, steady stream to form an emulsified dressing. Season with salt and pepper to taste.

Drizzle the dressing on the warm vegetables and gently toss to combine. Serve warm or at room temperature; or cool, cover, refrigerate and serve chilled.

Serves four.

Cook’s notes: To blanch the green beans, fill a large bowl with ice cubes and water. Bring a pot of salted water to a boil over high heat. Add the beans and cook for about 1 minute (they should brighten), then use a slotted spoon or Chinese skimmer to transfer them to the ice-water bath, leaving the beans whole.

The grilled vegetables can be refrigerated for several days and will pick up flavor from the dressing.

@Recipe nutrition:Nutrition values per serving: 340 calories, 29 g fat (4 g saturated) 21 g carbohydrates, 6 g fiber, 4 g protein, 0 cholesterol, 110 mg sodium.

Washington Post Top Tomato finalist Lauma Redin, Germantown, Md.