Ingredients:
Instructions:
Preheat your oven to 375°F (190°C).
Prepare the pie crust by mixing the ingredients and pressing it into a 9-inch pie dish, ensuring it covers the bottom and sides evenly. Set aside.
Heat olive oil in a large skillet over medium heat. Add onions and garlic, sautéing until softened, about 3-5 minutes.
Add shiitake mushrooms to the skillet. Cook, stirring occasionally, until the mushrooms have released their moisture and begin to brown, about 5-7 minutes.
In a medium bowl, whisk together eggs, milk, salt, and pepper until well combined.
If using cheese, stir it into the egg mixture.
Spread the mushroom mixture evenly in the prepared pie crust.
Pour the egg mixture over the mushrooms, ensuring they are evenly covered.
Bake for 35-40 minutes, or until the quiche is set and the crust is golden brown.
Remove from the oven and let it cool for a few minutes before slicing and serving.