Tom Yum Goong Soup (Thai Hot And Sour Shrimp Soup)

Ingredients

• 1 pound shrimp (peeled and deveined, reserve shells)
• 8 cups shrimp stock (or chicken stock or dashi)
• 1 inch piece galangal (chopped, or ginger)
• 4 kaffir lime leaves (chopped)
• 2 stalks lemongrass (peeled and chopped, or lemon zest)
• 1 cup shiitake mushrooms (sliced)
• 2 thai birdseye chilies (sliced thinly crosswise)
• 2 tablespoons fish sauce
• 3 tablespoons nam prik pao (roasted red chili paste, optional)
• 1 pound soba noodles (optional)
• 1 lime juiced
• 1/2 cup cilantro (chopped)
• 1/2 cup green onions (sliced into 1/2 inch pieces)
• roasted unsalted peanuts (roughly chopped, optional)