Preheat oven to 350℉. Line an 8x4 inch loaf pan with parchment paper.
In a large pan, heat the 1 tsp olive oil on medium high. Add in the scallions and saute for 1 minute. Add in the rough chopped spinach and saute until mostly wilted - 1 minute. Transfer to a paper towel lined plate to slightly cool. Pat dry as best you can.
In a large bowl, whisk together the eggs, olive and buttermilk until smooth. Sift in the flour, baking powder, salt and pepper to taste and mix to combine. Fold in the feta, mozzarella, dill and spinach. Transfer the batter to your pan and spread out evenly. Bake for 50-60 minutes or until a toothpick comes out clean. Allow to set in your pan for 10 minutes then transfer to a wire rack to cool completely.
Notes
You can also use 10 oz frozen chopped spinach - just make sure you wring it out as dry as possible. You can substitute kefir, Greek yogurt or whipped cottage cheese instead of the buttermilk.