We're (family, wife, husband, 13yo daughter, 17yo son) travelling next year to Europe. Son has been a vegetarian for a while, but on prior trips to Europe he's either not been vegetarian, or we travelled to countries where many restaurants included vegetarian items (the Czech Republic and Slovakia were quite easy, not surprising when you think about it, though the cuisine was not our favorite).
Next year will include Belgium and Paris, which I think will be more of a challenge (for dinner; lunch is always much easier). The rest of us foodies, most vocally our daughter, would rather not end up somewhere bad, dull, touristy or vegetarian-only to accomodate our son.
I actually think Paris will be easier than Belgium, as I've heard some places, such as Z Kitchen Galerie, have vegetarian mains (is that correct?); I know that Willie's Wine Bar and Mon Vieil Ami do, as we noticed them the last time we ate there, but we'd like to try other places.
But there are places that we would love to return to, such as Le Reminet in Paris, or the lovely little seafood places that we ate at in Brussels (de Koetse) and Bruges (Bij den Boer), that have very few vegetarian items listed, and I'm not sure if they'd be enough for a meal.
I have been told that European restaurants are not so accomodating to this sort of thing, but how unmannerly would it be for me to contact some restaurants beforehand, and see if they could provide enough food for a polite young vegetarian to have a reasonable dinner with his omnivore family? I wouldn't be asking for specially-prepared dishes, but whether they were serving enough vegetarian salads, side items, etc. that evening to comprise a meal, and whether that would be acceptable to the restaurant owners. If someone offered to modify a meat or seafood-based dish, or prepare an omelette, that would be even better, but not expected.
Generally, any other suggestions on this would be great. Most of the info I've found relate to vegetarian restaurants, which is not what we're looking for. I want to be understanding of his ethical choice, but also of our other family members who view travel as an excuse to eat a variety of great local dishes!