1. Prepare the Broth:

1. Heat Broth:
   • In a medium-sized pot, pour in 4 cups of chicken or vegetable broth.
2. Bring to Boil:
   • Place the pot over medium-high heat and bring the broth to a boil.

2. Add Aromatics:

1. Prepare Lemongrass:
   • Take 2 stalks of lemongrass, cut them into 2-inch pieces, and use the side of a knife to gently smash them. This helps release their flavor.
2. Prepare Kaffir Lime Leaves:
   • Tear 3-4 kaffir lime leaves into smaller pieces to release their aroma.
3. Prepare Galangal:
   • Slice 3-4 pieces of galangal into thin slices. If galangal is not available, you can use fresh ginger as a substitute.
4. Smash Chilies:
   • Lightly smash 3-4 Thai bird chilies with the side of a knife. Adjust the number of chilies based on your preferred spice level.

3. Infuse Flavors:

1. Add Aromatics:
   • Once the broth reaches a boil, add the torn kaffir lime leaves, smashed lemongrass, galangal slices, and bird chilies.
2. Simmer:
   • Reduce the heat to medium and let the broth simmer for about 5 minutes. This allows the flavors from the aromatics to infuse into the broth.

4. Add Mushrooms:

1. Prepare Mushrooms:
   • Slice 200 g (7 oz) of mushrooms. Button or straw mushrooms work well.
2. Add to Broth:
   • Add the sliced mushrooms to the pot and continue to simmer for 2-3 minutes, or until the mushrooms are tender.

5. Cook Shrimp:

1. Add Shrimp:
   • Add the peeled and deveined shrimp to the pot.
2. Cook Until Pink:
   • Cook for 2-3 minutes, or until the shrimp turn pink and are cooked through. Be careful not to overcook them, as shrimp can become tough if cooked too long.

6. Season the Soup:

1. Add Fish Sauce:
   • Stir in 3-4 tablespoons of fish sauce. This will add a salty, umami flavor. Adjust based on your taste preference.
2. Add Lime Juice:
   • Stir in 1-2 tablespoons of lime juice. This adds a tangy and refreshing flavor. Adjust to taste.
3. Add Sugar:
   • Stir in 1 teaspoon of sugar to balance the flavors. Adjust as needed.

7. Optional Step:

1. Add Thai Chili Paste:
   • For additional flavor complexity, you can stir in a spoonful of Thai chili paste (Nam Prik Pao) at this stage.

8. Finish and Serve:

1. Taste and Adjust:
   • Taste the soup and adjust the seasoning if necessary, adding more fish sauce, lime juice, or sugar as needed.
2. Garnish:
   • Remove the pot from heat. Ladle the soup into bowls and garnish with fresh cilantro.
3. Serve:
   • Serve hot, with extra lime wedges on the side if desired.