Frittata, quiche, crustless quiches...I honestly don't know the difference between the three, although I know there is one. I've even looked it up, but I still am unclear since everyone seems to have their own idea. Here's how I look at it: Quiche is like pie, with a crust. Crustless quiche is like pie, without a crust (and in my world always baked in a glass pie plate). Frittatas are usually done on the stove, but if they're baked then they are done in a square pan.
Is that an official definition? Not even a little. I make stuff up all the time.
At any rate, this is one I made up as I went along based on several odds and ends of things in my kitchen that needed to be used up or tossed. It would be good with a mixture of cheeses (pepper jack would be excellent), or with the addition of some bell peppers or mushrooms. But since I didn't have any of those things, they're not in this recipe. That's how I roll. Everything in this is an item I pretty much always have on-hand.