Spinach Quiche

Gather all ingredients. Preheat the oven to 375 degrees F (190 degrees C).

Melt butter in a medium skillet over medium heat. Add onion and garlic and saute until lightly browned, about 7 minutes.

Stir in spinach, mushrooms, feta, and 1/2 cup Cheddar. Season with salt and pepper.

Spoon mixture into prepared pie crust.

Whisk eggs and milk together in a medium bowl until combined. Season with salt and pepper.

Pour over the spinach mixture in pie crust, allowing egg mixture to thoroughly combine with spinach mixture.

Bake in the preheated oven for 15 minutes.

Sprinkle the top with remaining Cheddar and bake until set in center, 35 to 40 minutes longer.

Allow to cool briefly before slicing and serving, about 10 minutes.