In a medium saucepan, combine coconut milk, broth, ginger, and lemongrass and bring to boil over high heat. Add chicken, mushrooms, lime juice, fish sauce, sugar, and chili paste. Reduce heat and simmer until chicken is firm and opaque, 5 to 10 minutes. Discard lemongrass. Garnish servings with basil and cilantro.
Note: Nutritional analysis is per 1 1/2-cup serving.