A frittata and a quiche are both egg-based dishes. However, they have some key differences. A quiche is usually made with pastry crust and has a custard base, while a frittata does not have pastry crust or custard base and instead uses beaten eggs as the base. Additionally, frittatas usually have more vegetables and less cream than quiches. Furthermore, frittatas are typically cooked in a skillet on the stovetop and can be finished in an oven, while quiches are traditionally baked in an oven.