6 bone-in, skin removed chicken thighs (about 1 ½ lbs.)
Heat olive oil in a large pot over medium-high heat.Add onions, carrots, celery and garlic. Cook and stir until vegetables begin to soften, about 5 minutes.
Stir in thyme and marjoram and cook 30 more seconds.Add broth, tomatoes, celery leaves, bay leaves, salt & pepper. Bring soup to a boil. Add whole chicken thighs. Reduce heat to low and simmer, covered, for 30 minutes.
Carefully remove chicken thighs from pot.When cool enough to handle, cut meat from bone and chop into bite-sized pieces. Discard bones and return meat to pot. Remove bay leaves. Serve hot.