Swiss Cheese and Apple Frittata

When I first started making frittatas, they were usually with sautéed vegetables like zucchini and onions. But after developing the recipes for an article about the flat Italian omelets, I discovered numerous foods took well to the basic technique. For example, apples and cheese are often served together. I combined them with toasted almonds and onions into a savory appetizer or light main course. You can also cut a frittata into squares to serve as an hors d’oeuvre for 12 to 15 guests. In