In a blender add the coconut milk, fish sauce and banana. Purée until blended. Set aside.
Heat the ghee or oil in a large skillet or cast iron pan over medium heat. Add the yellow curry paste and stir. Cook for at least 2 minutes.
Add the pineapple and stir to caramelized and brown slightly, 2-3 minutes. Add the shrimp and sauté quickly for a minute or two, stirring to flip shrimp and turn pink. Remove shrimp and set aside.
Pour the coconut milk mixture over the pineapple, stirring to incorporate. Cook for another 3 minutes and add the diced zucchini. Cook another 2 minutes, stirring often. The sauce will thicken.
Add the shrimp back to the pan along with half the herbs and stir. Heat through for a minute. Serve with remaining chopped herbs and sliced lime over steamed rice.