Heat olive oil in a large heavy-bottomed pot over medium heat.
Add diced onion, carrots, and celery; sauté for 6 to 8 minutes until vegetables begin to soften.
Incorporate minced garlic, grated ginger, turmeric, cumin, salt, and black pepper; toast for 60 seconds to activate aromatics.
Add cubed chicken thighs to the pot and cook for 5 minutes, stirring occasionally to brown the exterior.
Pour in the chicken bone broth, scraping the bottom of the pot to release any fond.
Bring the liquid to a gentle boil, then reduce heat to low and simmer, covered, for 20 minutes until chicken is cooked through.
Stir in the coconut milk and baby spinach; continue to simmer uncovered for 3 to 5 minutes until spinach has wilted and the soup is heated through.
Remove from heat, stir in lemon juice, and garnish with fresh cilantro before serving.