Roast Pork And Mushrooms

• 2 scallions
• 2 lon without removing stems (inches)
• 130 gr chinese roast pork
• 80 gr mushrooms (fresh)
• 120 ml chicken broth
• 16 ml oil
• 5 gr cornstarch
• 5 ml soy sauce
• 5 ml sherry
• 2 gr sugar