To reconstitute something is to bring a concentrated or condensed food, such as frozen fruit juice, dried fruits etc. to its original strength by adding a liquid. Usually, but not always water.
Ragout (sounds Ragu)
This is a French word, which means stew, usually one made of meat or poultry and which is rather thick. In recent years, this word has become a rather clever restaurant menu marketing term because it is often used to describe just about any mixture that is somewhat soupy or stew like. Another example of chefs using smoke and mirrors to make food sound more sexy. In school, I used to always think of the guy from Laverne and Shirley, Carmine, the big ragoo! If your old enough to remember him then we can be friends….
Roux (sounds ‘Roo, as in Kanga)
Roux: is usually but not always, equal parts by weight, flour and fat cooked together and used to thicken sauces. … Clarified butter, vegetable oils, bacon drippings or lard are commonly used fats. Roux is used as a thickening agent for gravy, sauces, soups, gumbos and stews. There are many different levels of roux and the degree to which it is cooked, but we’ll cover that elsewhere.
Reduce / Reduction
Reducing is to cook by simmering or lightly boiling a sauce, broth, or other cooking liquid, until its volume is decreased in order to concentrate flavors, and naturally thicken the finished sauce or gravy. The end result is then your ‘reduction’ i.e. a red wine reduction, balsamic vinegar reduction etc.
Roast / Roasting
Roasting refers to a dry-heat cooking method used to cook foods, usually larger cuts of meat, and poultry (but other foods as well) uncovered, in an oven. Tender pieces of meat work best for roasting. The key being it is a ‘dry’ heat cooking as opposed to a pot-roast, which is more of a wet, moisture based heat.
Render / Rendering
A culinary term for melting and clarifying hard animal fat for cooking purposes. Rendering can be done by two methods: dry heat or wet heat. In both methods, the fat is slowly cooked until it melts and is then strained of impurities from the cooking process. Rendering something like bacon or duck skin, draws out the fat and allows the food to crisp up.