Don't worry Suibhne, as a somewhat irritating friend of mine once said "If you can't change the situation, change your mind".
You did not eat a Vol-au-vent, or even a Fly in the Wind, you ate a very small pie full of salad cream, and some other stuff, possibly a small shrimp.
Its provider may have had more middle class intentions, but it was just a tiny, open pie.
You have not been embourgeoised, if adopted French words are acceptable un the context, or if they are not, you can eat scraps from the squires table and still be a peasant.
Cheers,
Peasant and proud of it,
Dave