Heat the coconut oil in a large pot over medium heat until shimmering. While the oil heats, finely chop the onion and mince the garlic cloves. Slice the red jalapeno into thin rings, removing seeds if you prefer less heat. Once the oil is ready, add the onion, garlic, and jalapeno, cooking for 2-3 minutes until fragrant and the onion begins to soften. This creates a flavorful base that will carry throughout the soup.

Add the red curry paste to the softened aromatics and stir continuously for 1-2 minutes, allowing the paste to toast slightly and release its deep flavors into the oil. Add the bruised lemongrass stalk and galangal slices, stirring to combine. This short cooking time is crucial—it blooms the spices and creates a more complex, authentic flavor base rather than simply dissolving the paste into liquid.

Pour in the chicken broth and bring to a gentle boil, then immediately reduce heat to low and simmer for 20-25 minutes. This allows the lemongrass, galangal, and aromatics to fully infuse the broth with their subtle, aromatic qualities. I find this simmering time is essential for developing the authentic Thai flavors—rushing it results in a thinner taste.

Using a fine-mesh strainer, carefully pour the broth through to remove the lemongrass, galangal, and aromatics, reserving the infused broth in the pot. Discard the solids. Return the pot to medium heat and add the coconut cream, stirring to combine smoothly. Slice the chicken breasts into thin 1/4-inch strips and add them to the pot along with the halved or quartered mushroom caps. Simmer gently for 8-10 minutes until the chicken is just cooked through and opaque.

Once the chicken is cooked, remove the pot from heat and stir in the fish sauce, coconut sugar, and lime juice. Taste and adjust seasoning with salt as needed—I like to add the salt gradually since the fish sauce already provides significant saltiness. Let the soup rest for 1-2 minutes off heat so the flavors can fully marry together without any raw-alcohol bite from the lime juice.

Ladle the soup into bowls and top each portion with thinly sliced green onions and fresh cilantro. The bright, fresh garnishes provide a beautiful contrast to the rich, creamy soup and add a pop of color and herbaceous freshness that ties everything together.