Mise en place, literally "putting in place") is a French phrase defined by the Culinary Institute of America as "everything in place", as in set up. It is used in professional kitchens to refer to organizing and arranging the ingredients (e.g., cuts of meat, relishes, sauces, par-cooked items, spices, freshly chopped vegetables, and other components) that a cook will require for the menu items that he or she expects to prepare during his/her shift.
Recipes are reviewed to check for necessary ingredients and equipment. Ingredients are measured out, washed, chopped, and placed in individual bowls. Equipment, such as spatulas and blenders, are prepared for use, and ovens are preheated. Preparing the mise en place ahead of time allows the chef to cook without having to stop and assemble items, which is desirable in recipes with time constraints.
It also refers to the preparation and layouts that are set up and used by line cooks at their stations in a commercial or restaurant kitchen.
The concept of having everything in its place as applied to the work in a kitchen is likely to have become a staple around the time of Auguste Escoffier, who is well known for his development of the brigade system of running a kitchen.