Something edible, regardless of what it is called or supposed to be and this applies to all airlines, not just BA. Your 'savoury hot pie' can be just as inedible as anything else served on a plane. I stopped eating what they served on planes, decades ago.

Rubber chicken is rubber chicken regardless of how you dress it up and what you call it. I think the last time I was offered a real fillet mignon done medium rare properly was back in the 1970s or 1980s at the latest.

I probably could enjoy your 'savoury hot pie' if it was indeed the same as the one from your favourite home savoury hot pie shop Brisbane Road. But let's face it, it would be a mass produced, lowest cost, nearly unrecognizable something. You're talking about airline food. Airline food and edible don't belong in the same sentence. Best to slip a couple of real savoury hot pies into your carry-on and tip an FA a few dollars to microwave them for you.