Mise en place is a French phrase meaning "putting in place". In English it's pronounced (roughly) Meez ahn plahs. With respect to cooking this means gathering and measuring all of the components of your recipe prior to starting to cook. In cooking school before we could begin a recipe, we had to have our "meez" checked. Prior to cooking school, I wasn't really in the habit of "meezing" unless I was baking. For savory concoctions, I would work on the fly getting things together while other components were in process. In my head I saw the lack of "meez" preparation as more efficient. You chop your onions and begin sweating them in your pan with olive oil and then start chopping the next thing. Seems fine, right? Well, not really.