Melt chocolate and butter together in a bowl over water bath. Whist egg whites and sugar into a paste. Add flour into a paste and mix thoroughly. Fold paste paste into melted chocolate. You should end up with with dark fluffy mixture. Transfer into piping bag or container and let it cool for about half an hour. Grease your metal moulds with butter. Fill up each of them upto two thirds with chocolate mixture and cool in the fridge either for at least 1 hour or overnight. When ready bake in our premium combi oven for about 7 minutes. Or you can use ratio of 1 minute per every 10 grams of weight in mould. For example 70 grams of fondant mix takes 7 minutes to achieve runny centre and spongy texture on the outside. When baked let it sit for about a minute before taking out of the mould.