Remove the skin off the from the chicken thighs and pat dry with a kitchen towel. Season with salt and pepper.
In a large pot, heat olive oil over medium high heat.
Sear the chicken thighs for about 3-5 minutes until golden brown but not cooked all the way through. Remove and set aside.
Add onion, celery, grated carrot and all of the spices to the pot. Sauté until the vegetables are soft, about 5 minutes.
Add minced garlic and sauté for 1-2 minutes.
Add chicken broth and bring the soup to a simmer.
Add the chicken thighs back into the pot and simmer for 1 hour.
Skim off the foam from the soup.
After an hour, remove the chicken thighs from the soup and shred. Discard the bones and add the chicken back into the soup.
In a bowl, whisk together 1 egg yolk, yogurt and the juice of 1 lemon.
Temper the yogurt mixture by slowly mixing in a few spoons of the chicken broth.
Remove the soup from the heat and add in the yogurt mixture.
Serve Immediately and enjoy!