Preheat oven to 400°F. Use ghee, coconut oil or palm shortening to generously grease a tight-fitting 9-inch springform pan, or 9-inch deep dish pie plate. (If your springform pan does not fit together tightly, you may want to tightly wrap the outside of the pan with a large sheet of foil to help catch leaks, or use a deep dish pie plate instead).
Using a box grater, shred the potatoes (if using sweet potatoes, peel first). Rinse the shredded potatoes in a strainer; then press the shredded potato between a large layer of paper towels (or kitchen towels) to absorb excess moisture.
In a large bowl, add the shredded potatoes, 1/2 cup of fine diced yellow onion, 2 tablespoons of melted ghee or coconut oil and 1/2 – 3/4 teaspoon sea salt. Toss until combined.
Firmly press the shredded potato mixture evenly along the bottom of the prepared springform pan, making sure to press the potatoes up the sides of the pan at least one inch.
Bake crust for 15-18 minutes, until set. Then place on stove top to cool. Reduce oven temperature to 350°F.
While crust is baking, in a medium skillet over medium-high heat, add 1 tablespoon of ghee or coconut oil.
Sauté together the remaining 1/4 cup of yellow onion, red pepper and mushrooms for 4-5 minutes until veggies are softened. (If substituting with extra veggies instead of meat, sauté them with this onion mixture).
Next, add the swiss chard and stir until greens are wilted (about 2-3 minutes). Mix in the crumbled bacon or sausage, if using. Remove skillet from heat. Season with sea salt and pepper. Set aside.
Wipe clean the large bowl used for the potatoes. Then add the eggs, milk, basil, garlic powder, 1/2 teaspoon of sea salt and 1/4 teaspoon ground black pepper. Whisk until eggs are slightly frothy.
Add the veggie mixture to the bottom of the hash brown crust. Then, gently pour the egg custard over the top of the veggie mixture.
Place the springform pan on a large baking sheet (to catch any leaks) and place in preheated oven. (If you're using a pie dish, it's not necessary to use the baking sheet).
Bake at 350°F for 25 minutes until quiche is set. Remove from oven and allow to sit 3-5 minutes. Then gently loosen sides of quiche by running a knife along the side of the pan.
Remove springform pan and place on a serving platter. Serve with your favorite green salad and fresh sliced fruit.