Since my father's family originated from southern France near the Pyrennes the omelettes he often made for us on Sunday mornings, and sometimes for the evening meal were flat omelettes, typical of that region. Mom would make the classic rolled or folded omelettes, but dad always made his in the Basque style, similar to Spanish tortillas, or Italian frittatas.
Loosely based on La Piperade, the classic Basque omelette, my father's Sunday omelettes knew no bounds as far as ingredients. He always cooked them in the old, well seasoned, big black cast iron skillet, which now proudly hangs on my kitchen pot rack. First sauteeing some diced yellow onion, and building from there, adding this and that from the vegetable garden (such as Swiss Chard), or from the refrigerator, he usually included some ham, or bacon, sometimes cubed cheese, and leftover vegetables from the night before, etc.
And of course, always several eggs beaten with a fork, then poured over all, stirred gently for a short time, then allowed to set into a nice, thick omelette. To serve it was cut into wedges and usually placed right on the dining room table in the cast iron pan. Mom always liked to have a few shakes of Worchestershire sauce on her's.
It's a wonderful recipe, open to almost anything you may have on hand. Everytime I make it, I think of my father.