Heat the oil in a small non-stick frying pan and fry the potato over a low heat until it is browned and tender, this will probably take about 10 mins in all. Add the spring onion and fry for a minute then stir in the spinach.

Whisk the eggs lightly with a little seasoning and then pour them into the pan and cook until set on the base. Dot on the tomatoes, sprinkle on the cheese and grill until the top browns. Cool a little then slide out of the pan and cut into thirds.

Split the rolls and stuff them with a piece of omelette, sandwich together and halve.