In a 2-qt microwave-safe casserole, stir together broth, cornstarch, vinegar and soy sauce until smooth; stir in ham, snow peas, and onions. Cover with a lid; microwave on Hi for 10 minutes or until boiling, stirring twice during cooking. With a fork, stir broth in swirling motion. Without stirring, slowly pour iggs into swirling broth; then stir just until eggs are set in long strands.