In a large stockpot, bring chicken broth, coconut milk, brown sugar, curry, lemongrass and ginger to a boil. Add chicken and half the bag of kale (save rest for another use), pushing on kale with the back of a wooden spoon to submerge it in the boiling liquid. Cover pot and boil gently for 10 minutes. Add bell pepper, stir soup to make sure all greens are submerged, recover pot and continue boiling for another 10 minutes. Add green onions during the last minute or two of cooking time.
Stir in lime juice, serve into soup bowls, and sprinkle with cilantro.
Variation: Add a scoop of cooked fragrant jasmine or basmati rice to each bowl before you add the soup.