Preheat oven to 400F.
Heat avocado oil in a large skillet over medium high heat. Add in onion and cook until caramelized. Add in garlic and stir until fragrant. Add in chopped spinach and mix well.
Once canned tomatoes are rinsed and drained, add them to skillet along with pastry flour and basil. Mix well and turn off flame.
In a bowl, whisk together eggs, milk, salt, and pepper.
Scatter 1 cup of shredded cheese on the bottom of your pie crust. Then add vegetable mixture on top. Follow with the egg mixture. Finally, sprinkle the remaining 1/2 cup cheese on top.
Bake for 30 minutes or until top is golden. Cool a bit before serving so crust doesn't fall apart. Enjoy!