If you live in a tiny Hong Kong flat, with a proportionately small kitchen, and are trying to bake in a minuscule countertop oven, you probably get irked by books instructing you to bake something "on the middle shelf" - most countertop ovens have only one.
For many years, though, that was the only kind of oven I had, and every time I threw a dinner party, my guests would gasp in wonder, "You cooked it in that?" You need to know the limitations of such ovens, but cooking in them isn't all that difficult.
The main problems with countertop ovens are, firstly, that the heat source is very close to the food, and, secondly, that they have very little insulation, so the heat escapes quickly. I never attempted to bake anything as delicate or temperamental as a soufflé in a countertop oven: if a soufflé were to rise as high as you want it to, the top of it would probably burn from being too close to the heating element on the ceiling of the oven. Also, with most ovens (not just countertop ovens) the heat tends to concentrate at the back, and in order for whatever you're baking to cook and brown evenly, you need to turn it around about halfway through, which means you need to open the oven door, turn the pan back to front, then close the door again. Opening the oven door allows the heat to escape, and while this isn't a big problem with larger ovens (which are well insulated), when it comes to countertop models, the drop in temperature is drastic and could result in a delicate sponge collapsing.
It's better to use countertop ovens for baking sturdier foods. Most savoury dishes work fine, although if you're attempting to cook anything sizeable (such as a roast chicken), be sure there's enough space between the food and the oven ceiling, or the top might burn.
Cookies and muffins work well, as do tarts. You can use a countertop oven for most types of cake, but you should let them bake about three-quarters of the way (rather than half-way) before turning them around, because they can collapse if they cool too much before they're fully cooked.
When buying pans for a countertop model, make sure they're a little smaller than the interior - you don't want something that will be flush against the front and back of the oven, as air needs to circulate. And take care when cooking something fatty, because the splatters have a higher chance of coming into contact with the heating element, which could cause a fire.
Truc (tryk): noun, masculine, trick, gimmick, device. A French word for a chef's secret.