In a large heavy-bottomed pot, heat the olive oil over medium heat.
Add the ground turkey to the pot, breaking it into small crumbles with a wooden spoon until browned and cooked through.
Stir in the diced onion, carrots, and celery, sautéing for 5-7 minutes until the vegetables begin to soften.
Add the minced garlic, dried oregano, sea salt, and black pepper, stirring for 60 seconds until highly aromatic.
Pour in the chicken bone broth and add the dry lentils, stirring to combine.
Bring the soup to a gentle boil, then reduce the heat to low and cover with a lid.
Simmer for 25-30 minutes, or until the lentils are tender but still hold their shape.
Turn off the heat and stir in the fresh baby spinach until just wilted.
Finish by stirring in the fresh lemon juice to brighten the flavors before serving.