Lucknow has two distinct culinary styles, food for the commoner "Dastarkhwan e Aam" and food for the royals "Dastarkhwaan e Khaas". While it's very common for the royal food to travel to the streets via stolen recipes or via cooks that have been thrown out by the royals after getting bored, It's very rare to see the Dastarkhwaan e Aam dishes to be glorified to a royal status. There's a story about Nawab Shuja ud daula who while walking his Sooba was stopped by an immensely sweet and balanced aroma of spices from a travelers caravan, the source he saw was a handi all covered with coal and sealed. On going back he instructed his cooks to recreate the aroma and thus the art of Dum pukht was born, this is how food from the streets came first to the palaces of Awadh .The second example is the commoners super rich breakfast stew "Nihari" that gave the aam aadmi his share of warmth, carbs and protein that would keep him going till lunch and it went to the Royal Palaces on days when the Nawabs had to sleep through this period between their breakfast and lunch.
There is a lot of argument whether Nihari was soldier (sipahsalar) food from the by lanes of lal quilla that traveled to lucknow or wether it's a lucknow original phenomenon. Being a "Lucknowi" I openly side with the Lucknow bandwagon and hence in my last visit to get a better insight on the origin of this dish I met Haji Zuber who owns and runs the famous "Rahim ki Nihari" in Chowk. A sixty something gentleman, known as Haji Saab in the area, displaying an immense passion for life and food. "Of course Nihari Is from Awadh" he yells back at the question.
He talks at length about the fabled evenings of chowk as his great grandfather used to describe them to him. He is a graduate from the Lucknow University, which he thinks was quite a feat considering all he was doing was accompanying his grandfather to the markets and the kitchens and his culinary escapades to Delhi and Hyderabad. The only written will that is passed down in this family is the "ek mann Nihari ka Nuskha", the recipe of 40 kgs Nihari and the same has already passed down to his sons.
On being asked about the changes that he has had to make in the recipe so it suits today's taste and digestion (considering Nihari can be an immensely heavy dish to digest) he answers "None ", taste and the sublime feeling of immense pleasure after eating good food has not changed and will never change, as for the richness aspect "apna apna haazma "he jokingly concludes.