ex-Europe I've had FAs approach me before meal service to ask if I want the vegetarian meal or if I want to order from the menu. I almost always go off the menu. The Asian vegetarian meals I have taken have been underwhelming and way fewer courses than what my seatmates get. I've even had FAs say that they don't think the vegetarian meals are good. ex-Asia I've never had an issue with vegetarian meals.
I've also got food poisoning from a vegetarian meal.