Bake in the preheated oven for 35-40 minutes, or until the casserole is set and the top is golden brown.
Allow the casserole to cool for a few minutes before slicing and serving.
For a bit of a kick, add a pinch of red pepper flakes to the egg mixture. You can also substitute the spinach with kale or Swiss chard for a different flavor profile. If you prefer a meatier dish, add cooked and crumbled bacon or sausage to the mix. For a gluten-free version, ensure that all your ingredients are certified gluten-free. This casserole can be made ahead of time and reheated, making it a convenient option for busy mornings or when hosting guests.
