Romantic food is food which takes in to account the taste of the diners, is used to capture the occasion, is well presented and tastes delicious. This means that there can never be a precise definition.
Putting too much effort in to a romantic meal can actually have the opposite from the desired effect. Keep it simple. Make sure that distraction and interruption above all is avoided and remember that a romantic meal is about a lot more than the food.
The setting for a romantic dinner, the layout of the table, the wine which is to accompany the meal, the music which is to play softly in the background: all are equally as important as the food.
Cook something which you both like, present it properly and in the appropriate surrounds and perfection should not be far away...