Preheat your oven to 350°F (175°C).
In a bowl, combine almond flour, coconut flour, salt, and baking powder.
Add the cold, diced butter to the flour mixture and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.
Add the egg and water, mixing until a dough forms. Wrap in plastic wrap and refrigerate for 15 minutes.
Meanwhile, heat olive oil in a pan over medium heat. Add chopped spinach and sauté until wilted. Remove from heat and let cool.
In a bowl, mix ricotta, mozzarella, Parmesan, nutmeg, salt, and pepper. Stir in the cooled spinach.
Roll out the dough between two sheets of parchment paper to about 1/8 inch thick. Cut out circles to fit your tartlet pans.
Press the dough circles into the tartlet pans, trimming any excess.
Fill each tartlet shell with the spinach and cheese mixture.
Bake in the preheated oven for 20-25 minutes, or until the crust is golden and the cheese is bubbly.
Remove from the oven and let cool slightly before removing from the pans.
Garnish with fresh parsley before serving.
Variations & Tips
For a different flavor profile, try adding some crumbled feta or goat cheese to the filling. You can also incorporate sautéed mushrooms or sun-dried tomatoes for added depth. If you prefer a bit of heat, a pinch of red pepper flakes can be mixed into the cheese filling. For a gluten-free option, ensure that all your ingredients, particularly the baking powder, are certified gluten-free. These tartlets can also be made in advance and reheated in the oven, making them a convenient option for entertaining.