Preheat oven to 375 degrees F (190 degrees C). Grease a 9-inch pie plate.
Melt butter in a large skillet over medium heat. Add onion and garlic and sauté until softened, about 3 minutes. Add mushrooms, salt, and pepper and cook until mushrooms are lightly browned, about 5 minutes more.
In a medium bowl, whisk together cream, eggs, Parmesan cheese, and parsley. Pour into prepared pie plate.
Top with mushroom mixture and spread evenly. Bake in preheated oven for 25 minutes, or until golden brown and center is set.
Let cool for 10 minutes before serving.
Interesting facts
Chanterelle mushrooms are a type of wild mushroom that has a mild, earthy flavor.