1. Preheat oven to 400°.
2. Bring a large pot of salted water to a boil.
3. Add barley, return to a boil, and boil until tender, 30 minutes. Add vegetable medley during last 3 minute of cooking. Drain, cool slightly, toss with 2 teaspoons sesame seeds and reserve.
4. While barley is cooking, make salmon: Combine honey, soy sauce, sesame oil and chili flakes. Reserve 4 tablespoons of mixture. Place salmon on a baking sheet, and brush with honey-soy mixture. Bake until salmon is flaky, 15 minutes. Place reserved sauce in a small saucepan over low heat and keep warm.
5. Divide barley mixture among 4 plates, top with a salmon fillet and 1 tablespoon warmed sauce, and sprinkle with scallions and remaining sesame seeds.