Instructions

• Prepare ingredients: chop the onion, mince the garlic and ginger, thinly slice the red bell pepper into 1" long pieces, very thinly slice the mushrooms, thinly slice the green onions, squeeze 1/4 cup lime juice, and chop the cilantro. Cut 1 lime into wedges for serving.
• In a large heavy pot over medium heat, add 2 tablespoons vegetable oil and 2 tablespoons unsalted butter. Heat until the butter is melted and the mixture is shimmering.
• Add the chopped onion and sauté, stirring occasionally, until the onion is softened, about 3–4 minutes.
• Add 3 tablespoons green curry paste and 3 tablespoons yellow curry paste. Stir continuously for about 1 minute to release the curry aromas and combine the pastes with the onions.
• Add 3 large minced garlic cloves, 3 tablespoons minced fresh ginger, the sliced red bell pepper, and 8 ounces very thinly sliced mushrooms. Stir to combine and cook until the vegetables are softened, about 5 minutes, stirring occasionally.
• Pour in 8 cups low-sodium chicken broth and 2 cans (14 ounces each) full-fat coconut milk. Add 1½ tablespoons fish sauce, 2 tablespoons brown sugar, and ¼ teaspoon crushed red pepper flakes. Stir to combine.
• Add 3 cups cooked, shredded chicken to the pot and stir. Increase heat to medium-high and bring the soup to a gentle simmer, then reduce heat to low and simmer just until the chicken is heated through and the flavors meld, about 5–8 minutes. Do not boil vigorously.
• Remove the pot from the heat. Stir in ¼ cup freshly squeezed lime juice, the thinly sliced green onions, and ¼ cup chopped fresh cilantro.
• Taste and adjust seasoning with kosher salt and freshly cracked black pepper, as desired.
• Ladle soup into bowls and serve with lime wedges for squeezing over individual servings.