Heat the ghee or oil in a medium saucepan over medium heat. Add the onion and sauté for 4-5 minutes, stirring a few times, until softened and golden.
Add salt, zucchini and garlic and stir through the onion. Then add the turmeric, curry powder and pepper and stir through a few times to release the aromas.
Add the stock, coconut milk and fish sauce and stir through. Bring to boil, then turn the heat down to low. Cook for 10 minutes, simmering and covered with a lid.
Finally, add the juice of ½ lime and stir through. Serve with a few fresh coriander leaves on top.