Gratin of Potato, Spring Onion and Bacon

Potatoes are filling and inexpensive and potato gratins are a tasty, nourishing and economical way to feed lots of hungry people on a chilly evening.

This recipe could also include little pieces of bacon or a lamb chop cut into dice, so it can be a sustaining main course or a delicious accompaniment.

Serves 4 as a main course; serves 6 as an accompaniment