Melt the ghee in a large pot over medium heat, and sauté the diced onions, minced garlic, and grated ginger. Mix well with a wooden spoon, and let the vegetables cook until they are tender (approximately 20 minutes).
Once the vegetables are tender, stir in the turmeric, coconut milk, and water. Reduce the heat to low, and let the ingredients simmer for the next 10 minutes.
Transfer half the mixture to a blender and set it on high. Blend the ingredients until you get a thick, homogeneous liquid with a light-yellow color. Pour the mixture back into the pot and mix well. Add salt to taste.
Add the zucchini noodles to the pot and let them cook for a couple of minutes over low heat until they are tender.
Divide the zucchini noodles and yellow curry broth evenly between two large bowls. Top with fresh cilantro. Serve immediately and enjoy!