Special Note: Filo dough, found in your grocer’s freezer section, is easy to work with but requires some care. Prepare all of your ingredients before you start to assemble the pie and place them within easy reach. Work quickly, as the filo dries out at room temperature, making it brittle and hard to use. If you have to leave the dough for any reason, cover it with a damp tea towel.
Preheat oven to 350 F/ 175 C.
In a skillet, sauté the onions in olive oil or broth until soft, about 2-3 minutes.
Add spinach, salt, and pepper and sauté until wilted, about 5 minutes. Turn off the heat. If there is excess water in the skillet, drain it and save it for soup stock, etc.
Add dill and mix well. Put the mixture in a large bowl.
Grate the vegan mozzarella and crumble the vegan feta. Mix the two cheeses in a small bowl and set aside.
Pour the olive oil for brushing in a glass bowl. Brush the bottom of a 9x13-inch baking pan with a little bit of oil.
Place one filo sheet in the pan, fitting one edge of the dough against one long side of the pan, allowing the other half to hang over the edge.
Brush dough in the pan with some oil.
Fold the other half of the dough over the top and brush with oil.
Continue with half of the filo sheets, brushing each sheet with the olive oil.
After you have used half of the sheets, spread half the cheese mixture on top.
Cover it with the spinach, making sure the spinach is as dry as you can make it.
Spread the remaining cheese on top of the spinach.
Then top with the remaining filo sheets brushing each of them with the olive oil and assembling as you did with the bottom sheets.
When done, use a serrated knife to cut the pie lengthwise one way, and finishing it into squares. It is important to cut the squares before you bake the pie.
Bake for 60-70 minutes until it is golden brown on top. Begin checking at 50 minutes to make sure you achieve a golden crust. It should be golden, not brown.
Let it cool completely before cutting through (the melted cheese would have filled up some of the cut grooves) and serving.
You can use a mixture of spinach, chard, and kale or you may use 2 large packages of frozen spinach, thawed. Squeeze out as much of the water as possible after thawing.
You may also use vegan butter or a mixture of oil and melted vegan butter.