In a large bowl, whisk the peppercorns and egg whites together until foamy.
In a food processor, pulse the tomatoes, onions, celery, and ground beef just until incorporated.
In a large stockpot, combine the beef mixture, the egg mixture, bay leaf, the stock, and the thyme and salt. Bring to a boil, stirring constantly.
When the solids rise to the top and form a mass, reduce the heat and simmer, without stirring, for 30-40 minutes. Be sure not to disturb the mass as it could cause the consommé to become cloudy.
Remove the pot from the heat and strain the mixture through a fine sieve or a double layer of cheesecloth. Repeat if needed.
Your consommé should be clear and ready to enjoy!