A la Minute

À la minute is a French cooking term meaning “at a minute.” Restaurants that prepare food à la minute prepare food when it is ordered, and often such foods are prepared in front of the diners. 

”À la minute” has been cited in French since at least the 18th century, but became familiar to American diners since the 1960s. The dish known as minute steak (steak à la minute) was popularized in the early 1900s at Rector’s restaurant in New York City.
 
   
Wiktionary: a la minute
Adjective
a la minute (not comparable)
1. (cooking) prepared to order, not prepared in advance
2. (cooking, of a sauce) prepared in the same pan in which the item the sauce is served over or with was cooked
   
Google Books
The French Cook
By Louis Eustache Ude
London: John Ebers and Co.
1829
Pg. 87:
Cutlets a la Minute — {Chops at a Minute).

Google Books
French Chit-Chat; or, Recreations in French Conversation
By Jerome N. Vlieland
London: Matchett and Co.
1834
Pg. 178:
At a minute’s notice. a la minute.
 
Google Books
Washington:
The New York Times Guide to the Nation’s Capital
By Alvin Shuster
Washington, DC: R.B. Luce
1967
Pg. 266:
At midday almost all of the dishes are what might be called cooking a la minute — that is to say, simply prepared, grilled, broiled or sauteed foods such as rib steak maitre d’hotel or ...
 
Google Books
Work As You Like It:
A Look at Unusual Jobs
By John Ott andRosemary Stroer
New York, NY: Julian Messner
1979
Pg. 153:
As Carlisle points, most “joints” — that is, main courses or entrees — are a la minute, meaning cooked when ordered.
 
Google Books
Kitchen Confidential
By Anthony Bourdain
New York, NY” Bloomsbury USA
2000
Pg. 225:
A la minute is made-to-order from start to finish.
 
Google Books
The Professional Caterers Handbook:
How to Open And Operate a Financially Successful Catering Business
By Lora Arduser and Douglas Robert Brown
Ocala, FL: Atlantic Publishing Group
2006
Pg. 595:
A LA MINUTE – A style of cooking that is usually done in front of the guests and made to order.
 
Google Books
Modern Batch Cookery
By Victor Gielisse and Ron De Santis
Hoboken, NJ: John Wiley & Sons
2011
Pg. 40:
Dishes prepared a la minute are cooked “at the moment” of service to ensure high quality. Batch cooking is the equivalent of a la minute cooking when you are faced with preparing multiple servings at a single time.
     
Zagat
12/12/2012 10:51:00 AM
Service Week Glossary: A Guide to Restaurant Lingo
By Kelly Dobkin
(...)
“à la minute” - A dish that is prepared when the order comes in, not pre-assembled or pre-cooked. Essentially, made to order.