This is a very flavourful vegetarian main which is low enough in calories to have on a 5:2 Fast Day or as part of a calorie-counted healthy eating plan :-
Or serve as a side dish with chipolata sausages :-
The calculations for calories came out differently on MyFitnessPal than on my recipe card, below. Either way, no more than 265 kcals for the portions of gratin shown here.
The caraway seeds add a really interesting flavour.