PANCAKES: Sift flour and salt into a mixing bowl. Add egg and yolk. Gradually stir in milk.
Beat mixture until smooth, then fold in melted butter or oil. Set aside for up to 1 hour.
Just cover base of a frying pan with oil, pouring off surplus into a jug. Heat until starting to smoke. Remove from stove, then allow to cool slightly and pour in about 50 ml (1/5 cup) batter - just enough o coat the base of pan thinly (pancakes must be paper thin), tilting pan quickly to spread batter out evenly.
Cook for 1 to 2 minutes, or until bubbling lightly and edges start to curl. Flip pancake over to brown other side. Slide pancake out of pan and set aside while making other pancakes, 12 in all.
FILLING: Heat half the oil in a large ovenproof dish until hot but not smoking.
Place livers in dish, in a single layer. Season with chilli flakes, salt and pepper. Bake at 180 ºC for 10 minutes.
Remove, slice and divide between pancakes. Roll up pancakes and return to ovenproof dish.
Heat remaining oil in a large frying pan and when hot, but not smoking, sauté onion over low heat until softened, about 5 minutes. Add chopped tomatoes and water. Sprinkle with sugar, mustard powder, seasoning, lemon peel and crushed garlic. Cook until thickened.
Spoon mixture over pancakes, sprinkle with basil and pour cream over. Bake at 180 ºC for about 10 to 12 minutes.
Serve with young salad leaves, crisp cucumber slices, yellow tomatoes and thinly sliced onion dressed with lemon juice and olive oil and well seasoned.