An excellent thread. Many years ago, I was travelling to Singapore on a very regular basis. The CW breakfast main course was nearly always English Breakfast (or equivalent) or Fish Curry. Being a terrarian, the thought of a fish curry for breakfast is nothing short of revolting.

Guess what? The vast majority of passengers would opt for the English Breakfast. BA's estimates of likely demand was badly out (every time), and on every flight there was considerable outrage from the last few people to be served when their choice wasn't available (yeah yeah I've read the apology in the menu...).

After it happened to me three times (even changing where I sat in the cabin wasn't foolproof), I rang up BAEX and explained - there was no easy category (as mentioned by the OP), but the chap tried to help and put notes on the file etc.

Imagine my horror, on my next flight, to IAH, where I was denied a (slightly overcooked) fillet steak, as I had ordered a "special meal", which happened to be a nut roast.

My reluctant conclusion was that its generally better to take pot luck, and hope that alternative choices are available.