In a large Dutch oven or pot, add oil and heat on medium heat. Once the oil has heated, add the celery, onion, carrots, and garlic. Cook for 5-7 minutes, until onions are translucent.
Add the salt, pepper, thyme and bay leaf. Stir to combine. Add the broth and bring it to a simmer.
Meanwhile, in a medium bowl mix the egg whites, cottage cheese, and milk, until combined. Add the flour, salt, pepper, garlic powder, onion powder, and parsley. Mix until combined, do not over mix as this can make the dumplings too dense.
Add the shredded chicken to the simmering chicken broth.
Drop a heaping tablespoon full of the dumpling batter at a time into the simmering soup broth. Cover and simmer for 15 minutes, or until the dumplings are cooked all the way (use the toothpick test to see if it comes out clean). *Do not lift the lid during the initial 15 minutes of cooking. The dumplings need the steam in the pot to cook properly.
Remove bay leaf, add salt and pepper to taste, and serve!