Toasted Barley and Asparagus risotto

Name: Toasted Barley and Asparagus risotto
Ingredients: 12 ounces asparagus, trimmed, cut into 3/4-inch pieces; 2 cups pearl barley; 3 tablespoons butter; 1 cup finely chopped onion; 3 large garlic cloves, finely chopped; 8 1/2 cups (about) canned vegetable broth; 2 cups drained canned diced tomatoes in juice; 1/2 cup freshly grated Parmesan cheese; 1/2 cup chopped arugula or 3 tablespoons chopped fresh parsley; 2 teaspoons grated lemon peel