We recently flew Easy Jet from Pisa, Italy to London (Luton) on 6/30/2023. During the online booking process there was a simple way to indicate a nut allergy.
Upon boarding, the flight attendant approached my son, very nicely asked about the severity of his allergy and whether he had Epi-Pens. We were told that they would not be serving nuts (and seemed to indicate that they rarely do anymore anyway), and they would be making an announcement asking people to refrain from eating nuts.
The flight attendant said she could not guarantee anything beyond that, which we of course understood. They then played a pre-recorded message announcing there was a passenger with a nut allergy on board, and asked people to please refrain from eating any nuts they had with them. That message was in English. They then re-played it in Italian!
Clearly they have put thought ahead of time into trying to accommodate allergic passengers. So simple and easy, yet so thoughtful. They absolutely have our loyalty for all future European flights.