1 cup chopped herbs (basil, parsley, chives, dill)
1/4 cup feta, crumbled
1 lemon, grated zest
salt and pepper to taste
Peel potatoes and slice thinly with a mandolin or knife. Brush olive oil in a wide skillet and set over high heat. Reduce heat to medium and place a layer of potato slices in the skillet. Fry on both sides until golden brown and then place on a paper towel. Do this to all the potato slices.
Add the spinach to the same pan with a bit of water. Cook until wilted, about 3-4 minutes. Transfer to a sieve and press out any excess water.
In a bowl, whisk together eggs and ricotta. Add herbs, feta cheese and lemon zest. Roughly chop the spinach and add it to the mixture. Season with salt and pepper.
Preheat oven to 375 degrees. Spray a spring form pan. Line the bottom with the potato slices, overlapping where necessary to cover the whole bottom and sides. Pour in the ricotta mixture and put in the oven. Bake until firm and golden, about 40 minutes. Serve warm and cut in wedges.