Spicy Chicken Coconut Soup

• 3 lemon grass (minced)
• 2 chicken breast (halves)
• 2 green onions
• 1 lemon zest (grated)
• 1 slivered galangal root
• 1 ginger root
• 950 ml unsweetened coconut milk
• 475 ml chicken stock
• 85 gr straw mushrooms (whole)
• 50 gr slivered lemon (fresh)