Begin by pouring chicken or vegetable broth into a large pot and place it over medium heat. Warm the broth until it reaches a gentle simmer, about 3-5 minutes.

Once the broth is simmering, add the chopped lemongrass and kaffir lime leaves. Let it simmer for about 5 minutes, stirring occasionally.

Carefully incorporate the sliced mushrooms, bell pepper, and halved cherry tomatoes into the pot. Simmer for 5-7 minutes until the vegetables are tender.

Gradually pour in the coconut milk and stir to combine. Let the soup simmer for another 2-3 minutes until heated through.

Mix in the fish sauce, sugar, and chopped Thai chili peppers, adjusting seasoning to taste with salt and pepper. Simmer for another minute.

Gently add the peeled and deveined shrimp into the simmering soup. Cook until shrimp turn pink and opaque, about 2-3 minutes.

Remove from heat and squeeze in the fresh lime juice, stirring well.

Ladle the soup into bowls and garnish with fresh cilantro.