Melt butter in saucepan. Add scallions; cook 1 minute. Stir in toasted orzo; cook 4 minutes. Add lamb stock and heat to boiling. Stir in the bulgur wheat and reduce heat. Cook, covered, over low heat until the bulgur is tender and all liquid has been absorbed, 20 to 25 minutes. Turn off the heat and let the pan stand, covered, for 10 minutes.
Stir the herbs and garlic into the bulgur mixture, fluffing it with a fork. Serve immediately. Serves 4 to 6.