If you're looking for a breakfast or brunch option, this innovative veggie casserole is perfect. It combines the flavors of a classic quiche with the convenience of a casserole. The base is made with a mixture of eggs, milk, and cheese, which creates a creamy and custard-like texture. Spinach and mushrooms are added for a burst of flavor and nutrients. This casserole can be prepared ahead of time and baked in the morning for a quick and delicious meal. It's a great way to start your day with a dose of vegetables and protein.