Beat eggs and milk, add chives.
Heat a non stick 25cm frying pan and spray with oil.
Pour the mixture into pan and swirl around making a thin omelette.
Cook on a medium heat until egg is set on top and golden brown underneath. Cut omelette in quarters and place on each piece of bread. Top with John West Tuna, tomato and cheese and bake or grill until cheese is just melted. Finish with a spoonful of sour cream and freshly ground black pepper; serve immediately.