The chef has to tell you something about consommé.
Season the stock with salt and bring to the boil in a large saucepan. Combine the beef, vegetables, herbs, egg whites and peppercorns in a large bowl and mix well. Add 60 ml (2 fl oz) water and a little of the hot stock. Stir well and pour the mixture into the saucepan of hot stock. Return the mixture to the boil over medium heat, whisking and scraping the bottom of the pan to make sure that nothing sticks. Do not whisk or stir after the mixture boils. Reduce the heat and simmer for 45-60 minutes. As the mixture simmers, the egg white mixture will form a soft crust on top of the stock through which the impurities will rise and be filtered. (If there is no natutal break in the crust through which the stock can bubble up, gently clear a hole with a ladle.)
Scald a clean tea towel in boiling water and wring out to remove the moisture. Line a fine strainer with the tea towel and set it over a bowl. Slowly pour the stock through the strainer being careful noe to disturb the crust. Do not squeeze or press down on the contents of the strainer, or the stock will become cloudy; leave it to filter through the tea towel and strainer. Remove the strainer carefully and discard the contents. Degrease the stock in the bowl by pulling strips of paper towel across the surface.
Leave to cool.