• Preheat the oven to 350°F (if you're making the gluten-free crust instead of the regular crust, preheat the oven to 400°F).
• Add water to a medium or large pot over high heat with a steamer basket placed inside. Using a vegetable peeler, remove the skins off of the sweet potatoes. Cut the sweet potatoes into small cubes and add them to the steamer basket, then cover the pot. Steam the cubed potatoes until they are very soft and can be easily smashed with a fork.
• When finished steaming, put the sweet potatoes into a large bowl, add one tablespoon of butter, and use a potato masher, immersion blender, or food processor to mash the sweet potatoes until it’s a smooth puree. Set them aside to cool.
• Dice the onion and garlic. Then add two tablespoons of butter to a sauté pan over medium heat and let it melt. Once melted, add in the diced onions and cook for a minute, stirring occasionally. Add in the garlic and continue to cook for a few minutes, stirring occasionally, until the onions are almost see-through. Add in the spinach and cook until it's soft and wilted. Turn off the heat and set aside the vegetable mixture to cool.
• While the sweet potatoes and spinach mixture are cooling, make the pie crust using the instructions below.
• Before adding the eggs to the sweet potatoes, make sure they have cooled to lukewarm or room temperature so they don't cook the eggs. Add the salt, sage, thyme, and eggs to the sweet potato puree bowl and beat them into the puree until they're evenly mixed. Add the cooled spinach mixture and shredded cheese to the sweet potato mixture and mix together.
• Pour the sweet potato filling into the pie pan over the crust. Bake for 20-30 minutes at 350°F degrees. Then, sprinkle with parmesan cheese and bake for 10-20 minutes more. A toothpick or butter knife inserted into the middle of the pie should come out clean when it's done. If it's not done, bake for five-minute increments until a toothpick inserted comes out clean.
• Remove from the oven and let cool for several minutes before serving.

Regular Crust

• In a medium bowl, add flour, salt, and sugar and mix.
• Using a cheese grater, grate 1/2 cup of cold butter into the flour mixture then press and mix the butter and flour mixture together with your hands. It should be a chunky mix.
• Add the cold water to the bowl and mix, then knead the dough together into a ball with your hands.
• You can optionally line the pie tin with parchment paper to make serving the pie easier. You can use a rolling pin to roll out the dough into a circle and place it into the pie dish, or you can simply press the dough evenly into the pie tin. Set aside.

Gluten-Free Crust

• Preheat the oven to 400°F. In a medium bowl, mix the almond flour and salt together, then add room-temperature butter and cold milk. Mix with your hands. The dough should be firm but pliable.
• Press and form the dough into the pie pan. Bake at 400°F for about 10 minutes, so it’s slightly, but not fully cooked. Then, take the crust out of the oven, set it aside, and turn the oven down to 350°F.