Sous vide is a slow cooking process which involves immersing a vacuum-sealed product in a heated liquid.
The liquid is maintained at the desired temperature of the product.
This is usually done in water, but it can be done with fat as well.
Everything can be gotten for under $200.
Equipment
Water bath or circulator.
Plastic tub or large stock pot and a trivet.
A cover or lid for the container.
Applications
Keeping food warm.
Making confit with low levels of fat.
Making yogurt.
Precisely cooking risky dishes (e.g. liver mousse).
Warning
The heat from warm water may crack stone surfaces.