Step 1
Heat oil in a large heavy pot over medium-high heat. Cook scallions, garlic, and ginger, stirring frequently, until softened, about 4 minutes. Add carrot, jalapeño, and mushrooms and cook until softened, about 3 minutes. Add chicken, broth, coconut milk, and fish sauce. Bring to a boil, reduce heat, and cook until chicken is cooked through, 15–20 minutes. Transfer chicken to a plate and let cool slightly.