Heat the olive oil in a large heavy-bottomed pot over medium heat.
Season the chicken thighs with sea salt and black pepper, then sear them in the pot until golden brown on both sides.
Remove the chicken and set aside; add the diced onion, carrots, and celery to the pot, sautéing until the onions are translucent.
Stir in the minced garlic and dried thyme, cooking for one minute to release the aromatic oils.
Pour in the chicken bone broth, scraping the bottom of the pot to incorporate the flavorful browned bits.
Return the chicken to the pot, bring to a boil, then reduce heat and simmer for 20 minutes until the chicken is tender.
Remove the chicken, shred it into bite-sized pieces with two forks, and return it to the pot along with the chopped kale.
Simmer for an additional 5 minutes until the kale is wilted and the soup is piping hot.