Mongolian Lamb Stir-Fry

Ingredients

• 500g lamb back straps or sirloin
• 1 egg, whisked
• 2 garlic cloves, crushed
• 3cm piece fresh ginger, peeled, finely grated
• 2 tbsp dark soy sauce
• 2 tsp brown sugar
• 2 tsp cornflour
• ½ tsp bicarbonate of soda
• 2 tbsp black bean sauce
• 1 tbsp hoi sin sauce
• 1 tbsp dry sherry
• ½ tsp Chinese five-spice powder
• 1 tbsp vegetable oil
• 4 spring onions, thinly sliced
• 2 sticks celery, thinly sliced
• 1 head of broccoli, florets removed
• steamed jasmine rice, to serve
• coriander leaves, to serve