If a kitchen receives a ticket for a course that is to be sent as soon as it is ready, it is both "ordered in" and "fired" or "order fired". This is generally the case with all appetizers. It is also true of entrées that are ordered as an only course and not being grouped into a timed fire with other tables.
Every item that comes in on a ticket is considered ordered in. A ticket in a sit-down dining establishment will typically (not always) contain all of the food for the guests at a single table. From appetizers to mid-courses to entrées. The appetizers on the order are fired right away and will typically be ready to send to the table in five minutes or less. Entrées take more time to prepare so initial steps for large items are done on order such as grilling a steak or rendering a duck breast and the finishing steps are done on “fire”. Fires are typically designed to be anywhere from 5 to 10 minutes and will include all entrées for one or multiple tables. Line cooks at the various stations try to arrive at the pass with all of the items they must execute for the fire at the same time.
When an item is order-fired the kitchen must do all steps necessary to complete the dish. In the case of proteins this can take significant time. For example a steak could take 30 minutes to sear, roast, and rest, and a duck breast likely takes 20 minutes to render all of the fat and then hit medium rare through roasting and or basting. When this is the case, a waiter will likely inform the guest of the long wait time and offer an appetizer or something else for the guests to enjoy while they wait. Kitchens generally don’t like order fires when the entrée compositions are time consuming.
Expediting chef reading an incoming ticket: "Order in two bass same table. Order in lamb M.R. Order fire croquettes. Order fire caeser."
Sauté cook callback: "Order in two bass same table"
Grill cook callback: "Order in lamb M.R."
Garde manger callback: "Order fire croquettes, caesar"