The two main differences between quiche and frittata are: 1. A quiche has a pie crust on the bottom, whereas a frittata does not. A frittata is baked directly in a skillet or pan. 2. A quiche has a more creamy and custard-like egg filling—because it has a lower ratio of eggs to dairy (milk/cream). Whereas, a frittata uses more eggs and less dairy (milk/cream), resulting in a firmer, more egg-y texture.