Fillets of chicken are easy to prepare well. The small muscle is about half as thick as the big muscle, so when I, after dividing the two, slice the latter horizontally in two, I get three flat bits of fillet that will cook evenly. One can dust them with flour or not, one can cook them in butter or olive oil (or goose fat, hmmm), one can make a sauce with the cooking residue and white wine, or lemon juice or whatnot else, and spice it with anything from chipotle to fresh sage and back. Easy and quick – I’d guess quicker than the average time needed to warm up a frozen meal.
The only specialty feature is that fillet of chicken is à-la-minute food. Stop cooking when its done, not earlier (because this is bad for your health) and not later (every second equals an increase of one degree on the concrete scale).
Chicken fillet is low-calorie food and hence a recurring item in lunch restaurants. In lunch restaurants, many people come to choose from a small variety of items. Lunch restaurants typically cook the fillets whole, that is, the entire big bit of muscle, until very well done. Then the bits are piled up, waiting to be heated when needed, or kept warm in stainless steel containers. Chicken à la minute becomes brick à la hour. Yum.