Grilled Steak With Barley Salad

Name: Grilled Steak With Barley Salad
Ingredients: 1 1 1/4-to-1 1/2-pound boneless sirloin steak; Kosher salt and freshly ground pepper; 1 tablespoon Worcestershire sauce; 3 tablespoons extra-virgin olive oil; 1 cup quick-cooking barley; 2 small carrots, sliced; 2 stalks celery, halved lengthwise and sliced; 2 cups baby spinach; 3 ounces button mushrooms, stems removed, caps thinly sliced (about 1 cup); 4 scallions, thinly sliced; 1 teaspoon finely grated lemon zest, plus the juice of 1 lemon; 2 teaspoons whole-grain or dijon mustard