Thank you very much for your suggestions, hikermor and Russ.
A folding equivalent might be useful, as well, depending upon your local knife laws.
Italian knife laws are very idiosyncratic, but seem particularly keen against locking folders.
A smallish fixed blade might be more socially acceptable, especially if it looks like a kitchen knife or a gardening tool.
A knife I was considering is the Condor Mini Bushlore: it's cheap, small and has an unassuming wooden handle, a full tang blade of good carbon steel, and a handsome leather sheath.
https://www.amazon.com/Condor-Tool-Knife-Bushlore-Leather/dp/B004WMFI0YBut it has a scandi grind and a rather thick blade, so it might not be the best choice for food prep. I guess life is full of compromises...