bistro is a restaurant style characterized by being small and unpretentious, known to be typical of France.
from french bristot, restaurants of this genre became popular among the French during World War II. During this period, the women had to work to help supplement the monthly income of the family, so some decided to open the doors of their homes to sell homemade meals to the public.
In this sense, when you say "bistro dish" he is referring to a type of home-cooked, traditionally French meal at a low cost.
The exact origin of the term bistro is uncertain, but some stories say that when Paris was being attacked by the Russians in the early 19th century, soldiers invaded the town's small cafes and they shouted "bstro, bstro!”, Russian term that means “fast, fast” in the literal translation.
Bistro restaurants also often serve alcoholic drinks and coffees, which are usually accompanied by a few simple appetizers.
Bistros are spaces that value personalized interaction between the owner and customers. As a rule, in bistro restaurants there are no menus, and the cook himself /
chef of kitchen or waiter / waitress who informs the menu to the customer.See also: O meaning of à la carte.
Currently, however, the concept of a bistro restaurant is present in almost every city on the planet. But, contrary to the original meaning, contemporary bistros have a more sophisticated air, without losing the essence of the personalized relationship that exists between the chef and customers.