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.