Peppers, chillies and calf's liver

Ingredients

• 1 lb calf?s liver
• 2 tbsp peanut oil
• 1 red bell pepper, sliced into strips
• 2 shallots, thinly sliced
• 1 large leek, thinly sliced
• 2 large garlic cloves, thinly sliced
• 10 small red chillies
• 2 tbsp oyster sauce
• 2 tbsp soy sauce
• 2 tbsp water
• 1 tsp sugar