Sous vide
While the word itself may be confusing, cooking sous vide really isn’t.
The term is French for “under vacuum.” The entire cooking process involves keeping vacuum-sealed food at a constant, specific temperature while it cooks.
To do this, you need a special appliance called an immersion circulator. When set in a container of water, it heats that water to your specific temperature and circulates it. You then drop in your vacuum-sealed food, such as a steak, and it will cook slowly to the perfect doneness.