Grilled Flank Steak Salad with Tomatoes

["Recipe courtesy of Salad of the Day<\/a> (Weldon Owen Inc., 2012), by Georgeanne Brennan,\u00a0<\/em>reprinted with permission from the publisher<\/em>","Recipe courtesy of

Ingredients

For the mustard-herb vinaigrette

1⁄3 cup balsamic vinegar
1 1⁄2 Tbsp. chopped fresh thyme
1 1⁄2 Tbsp. chopped fresh marjoram
1 1⁄2 Tbsp. Dijon mustard
2 large cloves garlic, minced
Salt and freshly ground pepper
3⁄4 cup California Olive Ranch extra virgin olive oil

For the salad

1 flank steak, about 1 1⁄2 lbs. and 1 to 1 1⁄2 inches thick
1 red onion, cut into wedges
1 large head romaine lettuce, leaves torn into bite-sized pieces
2–3 tomatoes, preferably heirloom, cut into wedges, plus a handful of mixed cherry tomatoes, halved

Instructions

To make the vinaigrette, in a small bowl, whisk together the vinegar, thyme, marjoram, mustard, garlic, and 3⁄4 tsp. each salt and pepper. Add the oil in a thin stream, whisking constantly until the vinaigrette is well blended.
Place the steak in a shallow dish. Pour half of the vinaigrette over the steak and turn to coat both sides. Cover and refrigerate for at least 4 hours or for up to 24 hours, turning occasionally. Cover and refrigerate the remaining vinaigrette. Remove the steak from the refrigerator 30 minutes before grilling.
Prepare a charcoal or gas grill for direct-heat cooking over high heat. Remove the steak from the marinade, reserving the marinade, and grill the steak, turning once or twice and brushing with the reserved marinade for up to 5 minutes before the steak is done, until nicely charred and cooked to your liking, 10–12 minutes total for medium-rare. Let the steak rest for 5–10 minutes.
While the steak is resting, place the onion wedges on the grill and cook until softened and nicely grill-marked, about 5 minutes. Thinly slice the steak across the grain, reserving any juices that accumulate. Toss the lettuce with the reserved vinaigrette, and divide among individual plates. Top with the steak, onion wedges, and tomatoes. Drizzle the steak with the meat juices and serve.