2.Heat half the oil in medium frying pan, cook onion, garlic and pancetta, stirring, until onion softens. Arrange tomato slices over pancetta mixture.
3.Carefully pour combined egg, breadcrumbs and chopped basil into pan, cook, over low heat, until omelette is almost set.
4.Place pan under grill until omelette sets and top is browned lightly.
5.Carefully turn omelette, bottom-side up, onto serving plate, sprinkle with basil leaves; drizzle with combined remaining oil and vinegar.
Recipe is not suitable to freeze. You need a medium frying pan having a heatproof handle and a 20cm base for this recipe. If the pan handle is not heatproof, wrap it tightly in a few layers of foil; place the pan under the grill, but keep the handle away from the heat, if possible.