This sweet potato spinach quiche starts with a layer of thinly sliced sweet potatoes, and then it's filled with eggs, spinach, and feta for a healthy breakfast!
Slice sweet potato using a mandolin and line the bottom of a greased 9 x 13 baking dish.
Combine eggs and egg whites with seasonings, whisk them well, and pour them on top of the sweet potato.
Thaw (I used the microwave) and squeeze dry, frozen spinach, place on top of potato slices. Add feta on top of spinach.
Bake until eggs are fully set, about 35-45 minutes.