Thai Coconut Chicken Soup (Tom Kha Gai)

INGREDIENTS

• 1/2 medium onion, chopped into chunks
• 1 piece galangal, 1 inch long
• 200 grams sliced chicken breast
• 1 lime
• 1 tablespoon fish sauce
• 2 cups mushrooms (preferably straw mushrooms), chopped in half
• 1 piece lemongrass, white part only, chopped in half
• 1 teaspoon palm sugar
• 1 teaspoon coriander leaves
• 1 kaffir lime leaf, stem removed
• 1/2 medium tomato, chopped into chunks
• 1 to 2 small red chilies
• 1 shallot, chopped in thirds
• 500 milliliters coconut milk