3 tablespoons soy sauce
2 tablespoons vinegar
1 tablespoon brown sugar
1/2 tablespoon ground pepper
1 tablespoon salt
1. In a bowl, combine beef, vinegar, soy sauce, sugar, salt and pepper. Marinate for 30 minutes.
1. In a pan, heat oil and stir fry beef over low heat until golden brown.
2. Pour the marinade and teriyaki sauce, cover and simmer for 5-10 minutes until tender.
3. Adjust seasoning according to taste by adding more sugar, water or teriyaki sauce.
4. Transfer the beef to serving plate and pour thickened sauce on top.
5. Sprinkle with toasted sesame seeds and spring onion. Serve hot with sauteed vegetables and steamed rice.