Ingredients
1 top round steak (1 pound), about 1 1/2 inches thick
1 tablespoon Worcestershire sauce
Coarse salt and ground pepper
1 medium red onion, halved and thinly sliced
6 tablespoons white-wine vinegar
1 teaspoon sugar
2 tablespoons olive oil
1 head (10 ounces) red-leaf lettuce, torn into bite-size pieces
8 slices whole-wheat bread, toasted
2 tablespoons Dijon mustard
Preparation
Pierce steak all over with a fork. Place in a shallow dish, and rub with Worcestershire; season with salt and pepper. Let stand at least 15 minutes. In a small bowl, combine onion, 4 tablespoons vinegar, and sugar; season with salt and pepper. Let stand at least 15 minutes.
In a large skillet, heat 1 tablespoon oil over medium-high. Cook steak 6 minutes. Turn, and cover; reduce heat to medium. Cook until medium-rare, 6 to 8 minutes (if steak is browning too quickly, reduce heat to medium-low). Transfer to a plate; let rest 10 minutes. Thinly slice against the grain.
While steak rests, stir together 2 tablespoons vinegar and 1 tablespoon oil in a serving bowl; season with salt and pepper. Add lettuce, and toss.
Spread 4 slices of bread with Dijon; top with steak and onion. Close sandwiches; serve with salad.
