My method for consommé uses a meat grinder, but you can use a food processor and it works fine. If you don't have enough extra meat for the raft, use skinless chicken breasts or lean beef. You can make this ahead and store it in the fridge for up to a week. This general method works with any meat or fish.
1ouncedried mushrooms,any kind, soaked and chopped
10egg whites
A 2-inch piece of fresh rosemary,chopped
4bay leaves
2tablespoonskosher salt
12ouncestomato puree
Instructions
Make the raft by running the onion, carrot, celery, mushrooms and lean meat through a meat grinder, or by pulsing in a food processor until you have a rough mash. Don't puree it. Mix in the egg whites, rosemary, and bay leaves and chill for at least 4 hours, or up to overnight.
Pour the cold duck broth into a stockpot and add the salt.
Mix the tomato puree with the raft and add to the stock. Turn heat to medium and bring slowly to a simmer. Do not let it boil under any circumstances or you will ruin your consommé. Stir every couple of minutes until the raft begins to float on the surface. This takes a while, like 45 minutes.
When the raft has formed, poke a 1-inch hole in its center and let the consommé simmer gently for 1 hour and 15 minutes. Keep an eye on the hole and clear it if it gets clogged with debris.
Put a fine-meshed sieve over a container large enough to hold the consommé and line the sieve with a paper towel. Turn the heat to low on the consommé and ladle the soup through the sieve into the container. When you get to the bottom of the stockpot, pick out the raft and discard, then pour the remaining consommé through the sieve.
Chill the consommé or serve immediately. Add salt to taste before serving.
Notes
Note that this recipe starts with already made stock. If you need to make some, here is my recipe for duck broth.
Keys to Success
Classically, you would use the same meat in the raft as you would in the stock, but so long as you are vaguely close it'll work, i.e., meat with meat, fish with fish. Poultry can go with red meat, and seafood can go with fish, but don't get any weirder than that.
I can't stress enough how much you need to be patient. It takes a while for the raft to form, and then you need to make sure the broth doesn't boil furiously or it will break that raft.
If you are determined to do something with the leftover raft, feed it to your animals. Dogs love it, as do pigs, and maybe your cat will give it a go. It's no longer super tasty for humans, but it's safe to eat.
Consommé freezes well, and you can pressure can it. Follow your canner's directions, and shoot for 25 minutes at 10 PSI if you live from sea level to about 1000 feet.