Quick Mongolian lamb stir-fry with rice

Ingredients

• 2 tablespoons vegetable oil
• 500 grams lamb backstraps, trimmed, sliced
• 2 onions, cut into wedges
• 3 stalks celery, thinly sliced
• 1 green capsicum, seeded, sliced
• 1 carrot, peeled, julienned
• 2 garlic cloves, crushed
• 2 centimetre fresh ginger, peeled, grated
• 1 fresh long red chilli, chopped
• 1/4 cup chicken stock
• 1/4 cup soy sauce
• 2 tablespoons oyster sauce
• 2 teaspoons cornflour
• sliced spring onion, steamed rice to serve