One of the most interesting exercises in being a Temporary Vegetarian is eyeballing menus for alternatives. So far, I haven't failed to find something but I can imagine that if I were a permanent vegetarian, I would get tired of having just one or two choices. And vegans are much more limited. Fish, on the other hand, would greatly widen the selections.
At a Mexican restaurant, I was especially surprised to see the small number of choices: quesadilla was it until someone reminded me about chile rellenos.
The local bagel shops are a bonanza because there's a bagel with cream cheese or one of several egg and cheese choices.
Chinese restaurants carry many vegetable or noodle dishes, but with hazards. A purist has to be careful since the sauces may be meat-based or use fish sauce and the servers are not always truthful. I had noodles one time and mu shu vegetables another time.
Indian is easy, since many Indians are vegetarian.
Likewise, a local Thai restaurant has been easy.
At first, I thought sandwich shops are more difficult than expected, with just a couple of choices. But it's easy to leave off the meat, so most sandwiches can be vegetarianized. And don't forget the peanut butter and jelly on the kids menu!
Diners and cafes are easy, especially if they serve breakfast all day (pancakes, french toast, eggs).
Even barbecue has possibilities!