Combine cornflour, sugar, ginger and lemon rind in a mixing bowl. Mix well. Add steak and stir to coat.
In a large non-stick frying pan or wok, heat oil over a medium-high heat. Add steak to pan. Cook, stirring continuously, until browned, about 3 minutes. Sprinkle julienne of orange rind and pepper over steak. Cook, stirring gently, for 1 minute.
Add vinegar and orange juice, bring to the boil, reduce to medium and cook for 2 minutes.
Add green beans and snow peas, cook, stirring , until tender-crisp, about 3 minutes. Place beef mixture on a warm serving platter. Serve.