Start with a strong stock or broth. It must have great flavor and must be cold. Weak stock should be simmered down until becomes strong and richly flavored, then cooled down. Any fat should be skimmed off.
Combine the beef, mirepoix, egg whites, tomatoes, herbs, and spices in a stockpot. Mix vigorously with a wooden paddle or a whip.Professional kitchens use tall, heavy stockpots or soup pots a spigot at the bottom to make consomme. This allows them to drain off clarified stock without disturbing the raft: the layer on top of the stock consisting of vegetables, coagulated proteins and other. If you have one, use it.
Slowly stir in the cold stock while making sure that the stock is well mixed with the other ingredients.
Bring to a simmer very slowly, over a medium low heat, stirring occasionally.
When the simmering point is approaching, stop stirring. The clearmeat will rise to the surface at this point and form a raft.
Turn the heat down to low and simmer for 1 1/2 hours. Do not cover the pot and do not let it boil as boiling will break up the raft and cloud the consomme. Do not stir or disturb the raft at any point.
Strain the consomme through several layers of cheesecloth. If you are not using a stockpot with a spigot, you can siphon the consomme using a food grade tube of the appropriate length or ladle the consomme out carefully without breaking up the raft.Mine came out with quite a bit of grease on top due to meat not being lean enough I suppose. That's OK as the consomme will be degreased in the next step.
Remove all traces of fat from the surface very thoroughly. Strips of clean brown paper moved across the surface are effective in absorbing every last speck of fat without absorbing much consomme.
Adjust the seasonings. Kosher salt is preferred to regular table salt because it has no additives.
Refrigerate for up to 3 days or freeze for up to 3 months.