Peel the potatoes and cut them into ½ inch thick pieces.
Place the cut potatoes in a large pot. Add water to the pot until there is an inch of water above the potatoes. Bring to a boil on high heat. Reduce heat to medium high. Cook until soft 10 – 20 minutes.
Preheat the oven to 350°F.
When the potatoes are soft, drain off the water. Add the yogurt, ghee, and salt to the pot. Mash the potatoes until smooth.
When the potatoes are cool enough to handle, spray a 10 inch pie pan with non-stick spray. By hand, press potatoes into pie pan to form a crust. Make the layer as even as possible and without any holes. Brush the crust with oil.
Place pie pan on baking sheet (with edges). Bake 30 minutes.
Grate the zucchini (~2 cups), and chop the spinach.
Beat eggs and 1/8 tsp salt. Mix veggies into the eggs. Pour into the potato crust.