Step 1Combine the balsamic and white wine vinegars and the mustard in a small bowl. Whisk in the oil, add salt and pepper to taste then stir in the parsley.
Step 1Combine the barley and chicken broth in a small saucepan and bring to a boil over medium heat. Reduce the heat to low and simmer, uncovered, until the barley is tender but still firm, 35 to 45 minutes. Drain the barley and set aside.
Step 2Meanwhile, heat an outdoor grill on medium heat.
Step 3Combine the shrimp and the 3 tablespoons of dressing in a medium bowl; set aside.
Step 4Steam the asparagus and peas over simmering water until tender, about 5 minutes. Set aside.
Step 5Grill the shrimp, turning once, until pink and cooked through, about 1 1/2 minutes a side.
Step 6Arrange the barley, shrimp, asparagus, peas and greens on 4 plates. Drizzle with the remaining dressing.