If the airline sells food, check their terms and conditions. If there is nothing , you can bring your food and drinks. But they may have restrictions.
Would you go to a restaurant bringing your food? Do you think they would accept you ?
About your second idea, forget it. It is called black market. You don't pay taxes, you are not registered as a business, and so on.
Ecoute les orgues, Elles jouent pour toi...C'est le requiem pour un con